MIDI RS-232/RS-422 Converter - cinetix.de

MIDI RS-232/RS-422 Converter
User Manual for products delivered from July 2011 Status 10 January 2012
(new: optimized modes of operation. User programmable strings. ASCII command interpreter
If you need a manual for elder product versions, please order by email:cinetix@t-online.de.)
The MIDI RS-232/RS-422 Converter is the updated version of the "MIDI / Serial
Converter". This instrument is preferably used as a data converter between MIDI and
PC standard baud rates. Frequently used applications are: control of MIDI equipment in the
field of „building technology / art and architecture", bridge from PLC to MIDI, low cost MIDI
interface for professional media control systems. Futhermore, it is frequently used to control
any kind of equipment with RS-232 or RS-422 interface by a MIDI sequencer or keyboard.
The basic function is baudrate conversion between MIDI and RS-232/RS-422 without
changing the content of the transferred data bytes.
For better fitness to some commonly used equipment, in addition to the 1:1 baud rate conversion some
special modifications of the data contents are provided:
--- Generation of any data bytes and messages at MIDI OUT by means of ASCII text
input at the RS-232/RS-422 port and vice versa: any received MIDI message is transferred
into ASCII text to be transmitted at the RS-232 and RS-422 interface. This kind of data
modification is most useful to control MIDI equipment from PLC or PC software which is able
to transmit ASCII text but not the full 8 bit character set.
--- Transmission of arbitrary bytes out of the RS-232/RS-422 interface by means of
specially coded MIDI messages and vice versa: any bytes received at the RS-232 or RS-
422 port are transformed into specific MIDI messages. This way equipment with serial
interface is easily controlled by a MIDI sequencer or even from a live keyboard.
--- new in the actual firmware version is the feature to store up to 512 user specific strings
permanently (e.g. sequences of multiple commands) and to trigger the transmission of
these strings by a single MIDI message or a byte received at the RS-232/RS-422 interface.
--- useable as a MIDI merge- and through-box: MIDI style messages at MIDI IN and at the
serial port are consistently multiplexed and retransmitted at both interfaces.
--- For special data conversions and to run tests, two different command interpreters are
implemented. One of them is programmable for stand alone applications. In addition to
commands for transmission and reception of arbritrary data via MIDI and RS-232/RS-422,
4 analog inputs (0-5V) and 2 MOS switch transistors are built in. This way simple control
tasks, especially those including MIDI communication, may be solved with the Converter.
It is NOT allowed to use this instrument together with all safety critical applications, where
misfunction could result in personal injury oder noticeable material damage !
Elements at the front panel:
IN is a standard MIDI input
OUT is a standard MIDI output
A MIDI-Through connector is not provided

The power supply is designed for unregulated d.c. power supplies, min. 200 mA currrent
output. A simple in-plug supply with "europlug" is delivered together with the Converter.
Generally there are only small demands concerning the power supply. Any regulated or unstabilized DC
supply can be used with output voltages beween optimum 9 volt and max. 16 volt (which usually is the
max. output of an unregulated 12V AC/DC adaptor). The DC input is designed for a concentric low
voltage connector: external 5,0 - 5,5mm, internal 2,1mm. The positive polarity has to be connected
with the inner contact! Internally the MIDI RS-232/RS-422 Converter is protected against wrong
polarity: if wrong, the Converter is not powered.
The rotary switch "Ch / Mode" is used to select different baudrates and modes of
transformation between MIDI and serial interfaces:
(Zuordnung der Drehschalter-Stelllungen zu Funktionen nur gültig für ab Juli 2011 gelieferte Geräte !)
Ch./Mode Function
Serial
Baud
MIDI
MIDI Channel
Baud
0 1:1 transparent baudrate conversion 19200, 8N1 31250 ---
1 1:1 transparent baudrate conversion 38400, 8N1 31250 ---
2 1:1 transparent baudrate conversion config., 8N1 31250 ---
3 Baudrate conversion:ASCII text��MIDI byte 38400, 8N1 31250 ---
4 Baudrate conversion:ASCII text��MIDI bytee config., 8N1 31250 ---
5
6
7
8
9
A
B
C
Baudrate conversion: MIDI-Msg � serial Byte
but: ASCII text �MIDI byte
Baudrate conversion: MIDI-Msg � serial Byte
but: ASCII text �MIDI byte
Baudrate conversion: MIDI msg �� byte
Serial bytes are transferred into NOTE ON
Baudrate conversion: MIDI msg �� byte
Serial bytes are transferred into NOTE ON
Baudrate conversion:: MIDI-Msg �� Byte
Serial bytes are transferred to CONTROL CHANGE
Baudrate conversion:: MIDI-Msg �� Byte
Serial bytes are transferred to CONTROL CHANGE
Baudrate conversion:: MIDI-Msg �� Byte
Serial bytes are transferred to
PROGRAM CHANGE or CHANNEL PRESSURE
Baudrate conversion:: MIDI-Msg �� Byte
Serial bytes are transferred to
PROGRAM CHANGE or CHANNEL PRESSURE
19200, 8N1 31250 default/preset:1
config., 8N1 31250 default/preset:1
19200, 8N1 31250 default/preset:1
config., 8N1 31250 default/preset:1
19200, 8N1 31250 default/preset:1
config., 8N1 31250 default/preset:1
19200, 8N1 31250 default/preset:1
config., 8N1 31250 default/preset:1
D
Merge- and Through Box: retransmits data at MIDI IN
config., 8N1 31250
and serial interface "multiplexed" at both interfaces
---
E programmable standalone command interpreter config., 8N1 31250 default/preset:1
F simple ASCII text operated command interpreter config., 8N1 31250 ---
"MIDI msg �������� byte" describes a special mode of operation using MIDI channel messages or System
Exclusive messages to transmit arbitrary bytes via RS-232 and RS-422 Vice versa any bytes received
at RS-232 or RS-422 are transformed into differently formatted MIDI channel messages to be
transmitted from MIDI OUT. More details see below
"ASCII text �������� MIDI byte" describes a special mode of operation which transforms any hexadecimal
codes, which are entered at the RS-232 or RS-422 interface as ASCII text into the corresponding binary
bytes to be transmitted at MIDI OUT and in the opposite direction to “print“ any byte received at MIDI IN
as ASCII text via RS-232 and RS-422. More details see below

The MIDI channel which is used in generation or extraction of MIDI messages can be changed by the
user and saved permanently. The default preset at delivery is 1. Note: the MIDI channel numbers
described throughout this manual correspond with the „official“ way to assign MIDI channels!
As known, the channel value which is coded into MIDI status bytes always is one less! E.g: when the
MIDI channel is set to 3 by the user, always the value 2 is coded into status bytes, a NOTE ON will have
the status hex92 then. It is essential to keep this in mind when writing or configuring control software!
A dual LED does monitor presence of power, the active mode of operation and the data flow
via the MIDI interface:
During all modes of operation, the dual LED (made up of a red and a green LED) basically has an
amber colour.
When the the MIDI interface is receiving data, the green LED is going off for a short time, i.e. the LED
is flashing red.
When the the RS-232 or RS-422 interface is receiving, the red LED is going off for a short time, i.e.
the LED is flashing green.
When MIDI and serial interfaces are receiving simultaneously, the LED is flashing dark.
During a reset (is always performed when the rotary switch is turned) the LED goes off for
about one second.
Elemente at the rear panel:
Following hardware components are available here:
The connector "RS-232" is a standard RS-232 interface - wired as "Data Terminal"
(abbreviated "DTE").
At the connector "RS-422 / Option" in addition to a standard-RS-422 interface 4 analog inputs
and 2 transistor outputs are provided. Latter are accessable only when the rotary switch is in
position E and F, however.
Wiring of the RS-232 interface:
9 pin Sub-D connector (male), wired as "Data Terminal" ("DTE").
Pin connections:
Pin 1 --
Pin 2: RxD (serial receiverRS-232)
Pin 3: TxD (serial transmitter RS-232)
Pin 4: --
Pin 5: Signal Ground
Pin 6: --
Pin 7: RTS out
Pin 8: CTS in
Pin 9: optionally available +5V, max. 100 mA. An internal jumper has to be set.
Hints for external connections at the RS-232 rsp. RS-422 interface:
Internally the data receiver and data transmitter of both interfaces are each tied together. During transmission,
parallel use of both interfaces does not cause conflicts. But during a given period of time, only one interface
may receive data exclusively while a matching data packet is received, else incoming data will be mixed
together, resulting in garbage. Else no explicit selection or switching of the active interface is necessary.
3

The connection to an application device with RS-232 interface, like beamers or DVD players, is normally made
with a 1:1 standard cable like it is used to connect application with a PC. However we recommend to pay
attention to the interface specification of the attached device. To connect a PC with the RS-232 interface of
the Converter, a "Null Modem" cable has to be used !
For connection of the RS-422 interface, an adaptor cable has to be assembled in correscondence with the
pinout listed below.Inside the Converter a 120 Ohm termination resistor is activated at delivery. If this not
welcome in certain system configurations, it may be deactivated by pulling a jumper.
Users should pay attention to the fact that due to the different baud rates in priciple buffer overflow and as a
consequence loss or distortion of data is possible. To keep this risk as low as possible, the relationship of
baud rates should be selected in a way that the device which normally transmits most data is operated with the
lowest baud rate. If, for example, in a certain application essentially data of a MIDI device shall be evaluated via
RS-232, then 38400 would be the most appropriate serial baud rate. For another application, however, when a
PCL controls a MIDI mixer, 19200 baud would be more appropriate. For transmission of MIDI data with RS-422
over a long distance 31250 (optionally configurable at rotary switch positions E and F) or 38400 Baud is best.
Latency time is typically 0.5 to 3 milliseconds, depending on mode of operation and data types.
For each data direction, a queued buffer memory of 4 kilobytes is provided, which can efficiently suspend peaks
of data load. But if permanently more data are received than can be transmitted, a buffer overflow is
inavoidable. MIDI generally provides no possibility of handshake. The RS-232 interface is equiped with a
RTS/CTS hardware handshake which can be activated by command (inactive at delivery). For RS-422 no
handshake is provided.
Wiring of the connector "RS-422 / Option":
15 pin Sub-D connector (female)
Pin connections:
Pin 1: AnalogIn #0, Digital I/O#0, counter and encoder input
Pin 2: AnalogIn #1, Digital I/O#1, sense detection of encoder
Pin 3: AnalogIn #2, Digital I/O#2
Pin 4: AnalogIn #3, Digital I/O#3
Pin 5: Rx+ (RS-422)
Pin 6: Rx- (RS-422)
Pin 7: Tx- (RS-422)
Pin 8: Tx+ (RS-422)
Pin 9: MOS transistor #4 (open drain output), pulse witdth modulation
Pin 10: MOS transistor #5 (open drain output), square wave generation, pulse witdh modulation
Pin 11: Signal Ground
Pin 12: Signal Ground
Pin 13: Signal Ground
Pin 14: +5V (max.100mA totally)
Pin 15: +5V (max.100mA totally)
Installation and first operation:
Connections of power supply and data cable can be done in any order. The connectors at the
"RS-232" and "RS-422 / Option" connectors may be plugged and pulled out arbitrarily while
power is present or not.
If an external sensor or actuator is attached a first time, a functional test of this component should be
performed immeditately (rotary switch pos. E or F). If any malfunction is observed, the power has to be
switched off immediately and the problem should be analysed. Especially avoid to connect port lines
configured as output with outputs of externally connected devices ! This may destroy the Converter as
well as the external component !
The Converter is delivered with default settings as follows:
Serial baud rate = 19200: when the rotary switch is in pos. 2,4,6,8,A,C,E,F.
Serial baud rate = 31250 (MIDI): when the rotary switch is in pos. D (products delivered from 2012)
= 19200 when the rotary switch is in pos. D (products delivered in 2011)
At all rotary switch settings else, the baud rate is fixed by the switch position.
4

How to change the baud rate: this is only possible at switch positions E and F - the setting is adopted
in any "configurable" switch setting. After power is put on or the rotary switch is turned, the device is in
state of automatic baudrate recognition for about 1 second. Then send repeatedely any ASCII code via
RS-232 or RS-422. Best reliability is achieved with lower case 'm' or upper case 'U' . The SPACE key
works unreliably ! To change baud rate from MIDI equipment: send NOTE ON or CONTROL CHANGE
with all data bytes = hex 55 (decimal 85) or hex 6D (decimal 106)
Only standard baudrates 2400, 4800, 9600, 19200, 38400 Baud are detected, additionally MIDI (31250
Bit/s). If another baud rate is sent, the nearest fitting one is taken. Because it is sometimes difficult to
send MIDI data to the serial interface, the MIDI baud rate can be set directly with the ASCII command
~~ (two times 'tilde' in immediate sequence). The detected baud rate is stored permanently and
automatically reactivated at next system start if the rotary switch is in pos. 2,4,6,8,A,C,D,E or F. I.e. the
detection prodecure is only necessary when the baud rate shall be changed or is unknown.
MIDI channel = 1: relevant at rotary switch positions 5 to C.
During conversion serial byte � MIDI, this channel is inserted to MIDI messages. In the opposite
direction MIDI � byte, exclusively MIDI messages with this channel are converted into serial bytes.
How to change: Use a terminal program. Turn rotary switch to pos. F, set baud rate if necessary. After
a hello prompt is shown, type "N" (case independent), followed by the desired MIDI channel (ASCII 1 to
16), then . This setting is stored permanenty until it gets changed later.
No handshake (RTS/CTS Handshake OFF): relevant at all rotary switch positions
How to change: Use a terminal program. Turn rotary switch to pos. F, set baud rate if necessary. After
a hello prompt is shown, type the ASCII text "Q1". To deactivate handshake, type "Q0". This setting is
stored permanenty until it gets changed later.
Data protocols of baudrate conversion
In the "1:1 transparent modes of operation " (rotary switch positions 0,1,2) all
data received at MIDI IN are retransmitted unchanged from the RS-232/RS-422 interface
and vice versa , but in a different baud rate.
At rotary switch position 2, the RS-232/RS-422 interface operates with the baudrate that was
set at rotary switch position E or F. Especially the MIDI baud rate 31250 may be selected.
This way, the MIDI /RS-232/RS-422 converter is useable to transmit MIDI data over a longer
distance, for example combined with a "Cinetix MIDI/RS-422 Expander".
No error messages are generated because no formal errors are possible. Nevertheless false data input will
produce semantic errors
The "ASCII text �� MIDI byte" mode (rotary switch positions 3,4,5,6) is
specially useful to control MIDI equipment by means of equipment with ASCII capable
serial interfaces like PLC. Text sequences entered at the RS-232 or RS-422 interface are
transformed into binary bytes and retransmitted via MIDI OUT.
In this mode, every binary byte is represented as text as follows: it’s hexadecimal code is described by two
characters (digits or any of the letters A,B,C,D,E,F). All letters may be entered upper or lower case. One-digit
hex numbers (less than decimal 16) can be expressed by a single character or with a leading zero. The SPACE
key marks the end of a byte as well as the CARRIAGE RETURN character (hex D). The LINE FEED character
(hex A) is ignored without effect or response. Every invalid text input is echoed with a question mark ‘?’ at the
RS-232 and RS-422 interface.
This way MIDI I/O can be performed with software or hardware equipment which only sends ASCII strings and
is not able to handle 8 bit data communication - or for tests even by hand on a terminal program.
Accordingly bytes received at MIDI IN are retransmitted at the RS-232 interface formatted as
ASCII text as described above (only rotary switch positions 3 and 4).
The setting of the rotary switch only has an influence on the baud rate at RS-232 and RS-
422. MIDI channels are are implicitely contained in the ASCII text data.
5

Example: To send a CONTROL CHANGE status byte hexB1 (=decimal 177) at MIDI OUT, the following text is
entered at RS-232 or RS-422: "B1 or "..
Opposite example: a keyboard touch of the note c (= MIDI value 48 = hex30 ) with standard velocity (decimal
64 = hex 40) at MIDI channel no.1 will produce the following ASCII text at the RS-232 side: “90 30 40 “
In "MIDI Msg �� Byte" mode (rotary switch positions 5 to C) MIDI messages are
transformed into single bytes at the serial port and vice versa. This mode of operations is
particularly designed to control equipment with a RS-232 or RS-422 interface by means
of MIDI messages.
When MIDI messages are to be transformed into serial (RS-232 and RS-422) bytes, the four
methods, which are described below, can be mixed arbitrarily while the rotary switch is in
any of the positions 5 to C. Only MIDI messages coded with the preset MIDI channel (default
= 1) or with the Cinetix MIDI manufacturer ID are captured from the MIDI stream and
retransmitted.
However for the opposite conversion from serial to MIDI, every byte received at the serial
port is transformed into a MIDI message (MIDI channel as configured, default =1) by a
specific method which corresponds to the position of the rotary switch (only switch
positions 7 toC ! Details see below).
The actual firmware version (Converters delivered from July 2011) provides a feature to
overwrite these standard transformations by transmission of user programmed strings, which
are kept stored permanently. Details see lower at page 9ff.
Method 1:
If MIDI IN receives a message of the type NOTE ON, POLY KEY PRESSURE ( or NOTE
OFF) (MIDI channel as configured, default =1) this message is transformed into a byte as follows,
which is immediately retransmitted at the serial port (RS-232 and RS-422):
1st data byte (note value): becomes bits 0 to 6 of the serial byte.
2nd data byte (velocity):
--- if the “velocity“ is in the range 1 to 126, bit 7 of the serial byte becomes = 0 ("printable
character", elementary ASCII code set)
--- if the “velocity“ is = 127, bit 7 of the RS-232 byte becomes = 1 (expanded ASCII code set)
--- by default MIDI messages with “velocity“ = 0 and NOTE OFFare ignored (a protection
against messages which are sent automatically at the end of a key touch). Optionally this
blocking may released by the command % (see description of the % command p.10 and p.14).
Example: A keyboard touch of the note d (=MIDI value 50 = hex32) with moderate velocity will release a byte
with binary value hex 32 , which is printed as ASCII ”2“.
Method 2:
If MIDI IN receives a message of the type CONTROL CHANGE or PITCH WHEEL CHANGE
(MIDI channel as configured, default =1) this message is transformed into a byte as follows, which is
immediately retransmitted at the serial port (RS-232 and RS-422):
1st data byte (controller no. or pitch LSB): bit 0 of this data byte becomes bit 7 of
the serial byte.
2nd data byte (controller value or pitch MSB): results in bits 0 to 6 of the serial byte.
This means: any CONTROL CHANGE message from controller no. 0 (or any controller else with
even number) produces a "printable character" of the elementary ASCII code set 0 to 127. Any
CONTROL CHANGE message from controller no. 1 (or any controller else with odd number)
produces a byte of the expanded ASCII code set 128 to 255.
6

Example: From the CONTROL CHANGE message hex B0 51 75 respectively decimal 176 81 117 the byte
hexF5 respectively decimal 245 is generated and retransmitted via RS-232 and RS-422.
Method 3:
If MIDI IN receives a message of the type PROGRAM CHANGE or CHANNEL PRESSURE
(MIDI channel as configured, default =1) this message is transformed into a byte as follows, which is
immediately retransmitted at the serial port (RS-232 and RS-422):
The MIDI data byte is copied into bits 0 to 6 of the serial byte. Additionally:
Any PROGRAM CHANGE message clears bit 7 of the serial byte (= 0) ,
i.e. produces a “printable character” of the elementary ASCII code set 0 to 127
Any CHANNEL PRESSURE message sets bit 7 of the serial byte (= 1),
i.e. produces a byte in the range 128 to 255
Example: The PROGRAM CHANGE message hex C0 41 (=decimal 192 65) produces the byte “A“ at the
serial port, while the corresponding CHANNEL PRESSURE message hex D0 41 causes serial transmission of
the byte hexC1.
Method 4:
If a System-Exclusive message with the Cinetix manufacturer ID is received at MIDI
IN, it is transferred to a message at the serial port (RS-232 and RS-422) as follows:
The SysEx header is not retransmitted.
The SysEx header always consists of the same 4 byte sequence, which is equal to the
Cinetix SysEx manufacturer ID:
hexadecimal: F0 00 20 5D
or decimal: 240 0 32 93
The data body which follows the SysEx header is retransmitted via RS-232/RS-422
until the EOX byte (hexF7 =decimal 247) is received, which terminates this data transfer and
is not retransmitted.
According to the MIDI standard the bytes in the data body are restricted to values
between 0 and 127. Normally every byte of the data body – especially sequences of text – is
retransmitted without modification at the serial interface, apart from the following
exception: The two bytes following a “backslash” ’\’ are the ASCII representation of
the hexadecimal code of the character which is to be transmitted via RS-232 and RS-
422.
This way even bytes with values between 0 and 32 as well as those with values between 128 to 255 can be
comfortably transported in a System-Exclusive message. NO SPACE is allowed between the backslash and the
two bytes. If byte values less than hex10 are to be transmitted, a leading zero HAS TO be inserted between the
backslash and the hex digit. For instance, the phrase \0D\0A produces a CarriageReturn + LineFeed at the
serial side. If a backslash actually has to be sent via RS-232 it is coded in the SysEx message as follows: \5C. If
the hexadecimal code which follows the backslash contains invalid characters or any errors else, it is converted
and retransmitted via RS-232 in an uncontrolled way! Neither an error message is returned nor the whole
transmission is cancelled because most common MIDI equipment is not able to handle error feedback!
Transformation of RS-232/RS-422 bytes into MIDI messages: (switch pos. 7 to C)
The command types described above can be mixed arbitrarily when data are sent from
MIDI to RS-232, but in the opposite direction of information transfer serial � MIDI a specific
7

MIDI output format has to be selected with the rotary switch. The MIDI channel which is
inserted into these messages is selected by configuration (default = 1).
Rotary switch positions 7 or 8: Every byte which is received at the RS-232/ RS-422
interface generates one NOTE ON message of the following format:
1st data byte (note value): takes over bits 0 to 6 of the serial byte. According to
the MIDI standard, bit7 is always set to zero.
2nd data byte (velocity):
is equal to 64 (hex40), if bit 7 of the serial byte is = 0
("printable character", elementary ASCII code set).
is equal to 127 (hex 7F), if Bit 7 of the serial byte is = 1
(expanded ASCII code set)
Example: If the rotary switch is in position 7 and the active MIDI channel is default =1, the byte “x” (hex78 ,
decimal 120) which is received at the serial port, will be converted into the NOTE ON message hex 90 78 40
(decimal 144 120 64).
If the special german letter “Ä“ (Code hexC4, decimal 196) is received at the serial port, it will be converted into
the NOTE ON message hex 90 44 7F (decimal 144 68 127) (applies only to Windows operating system).
Rotary switch positions 9 or A: Every byte which is received at the RS-232/ RS-422
interface generates one CONTROL CHANGE message of the following format:
--- 1st data byte (controller no.) = 80 (hex50) if Bit 7 of the serial byte = 0
("printable character", elementary ASCII code set)
--- 1st data byte (controller no.) = 81 (hex51) if Bit 7 of the serial byte = 1
(expanded ASCII code set)
--- Bits 0 to 6 of the serial byte are copied without modification into the 2nd
data byte of the CONTROL CHANGE message (controller value). According
to the MIDI standard, bit7 is always set to zero.
Example: If the rotary switch is in position 9 and the active MIDI channel is default =1 the byte „%“ (hex25 ,
decimal 37) which is received at the serial port will be retransmitted at MIDI OUT as the byte sequence hex B0
50 25 (decimal 176 80 37)
If the special german letter “ü“ (Code hexFC, decimal 252) is received at the serial port, it will be converted into
the CONTROL CHANGE message hex B0 51 7C (decimal 176 81 124) (applies only to Windows operating
system).
Rotary switch positions B or C: Every byte which is received at the RS-232/ RS-
422 interface generates one PROGRAM CHANGE or CHANNEL PRESSURE message of
the following format:
--- A PROGRAM CHANGE message if bit 7 of the serial byte is = 0
("printable character", elementary ASCII code set).
It’s data byte is equal to the RS-232 byte.
--- A CHANNEL PRESSURE message if bit 7 of the serial byte is = 1
(expanded ASCII code set).
It’s data byte is equal to the serial byte MINUS 128 !
Example: If the rotary switch is in position B and the active MIDI channel is default =1 the byte „%“ (hex 25 ,
decimal 37) which is received at the serial port will be retransmitted at MIDI OUT as a PROGRAM CHANGE
message consisting of the byte sequence hex C0 25 (decimal 192 37)
If the paragraph sign “§“ (Code hex A7, decimal 167) is received at the serial port, it will be converted into the
CHANNEL PRESSURE message hex D0 27 (decimal 208 39) (applies only to Windows operating system).
8

Programmable Strings (new from July 2011)
Up to 512 strings with each length of max.126 bytes may be entered permanently
("programmed") into the memory of the microcontroller while the rotary switch is in
positon F. (Details how "programming" is performed, see below)
Transmission of the programmed strings is active at rotary switch positions 5 to C
("serial � String" only at positions 7 to C). Strings programed for direction "serial � String"
may be transmitted at switch position F by use of command S (details see below).
Each 128 memory segments are reserved for:
--- NOTE ON messages (alternative POLY KEY PRESSURE too)
--- CONTROL CHANGE messages (alternative PITCH WHEEL CHANGE too)
--- PROGRAM CHANGE messages (alternative CHANNEL PRESSURE too)
When any of these MIDI messages is received, the assigned string (if programmed) is
transmitted from the serial interface instead of the standard conversion described
above, i.e. the string with the number which is equal to the value of the 1st data byte of the
MIDI message (note pitch, controller number, program number,....)
As an alternative it is possible to retransmit specified ones or any strings from MIDI OUT, this
provides a kind of patch capability.
If no string is programmed for a specific MIDI message or a previous string has been deleted,
the standard conversion as described above will be transmitted from the serial interface. At
delivery, no strings are preprogrammed.
--- Bytes with ASCII codes 0 - 127 at the serial interface trigger transmission of the
assigned programmed string from MIDI OUT, appropriate configuration provided. If no
string is programmed for a specific ASCII code or a previous string has been deleted, the
standard conversion as described above will be transmitted from MIDI OUT. At delivery, no
strings are preprogrammed.
As the strings are allowed to contain up to 126 bytes, it is easily possible to release a long
sequence of commands with a single MIDI message or a single serial byte. Mathematical or
logical operations are not possible within strings. Only exactly the programmed string may be
transmitted.
Various filter options refine the decision if the programmed string or the standard
conversion shall be transmitted in a given situation:
With the optionally applicable command !1 bis !16 (details see below) the string trigger can
be restricted to a given MIDI channel. If decimal 80 (hex50) is added to the parameter, the
message is sent to MIDI OUT instead of the serial interface. Furthermore, this redirection
may be activated in general by the command %.
The command !0 does activate string trigger by messages with any MIDI channel.
The ! command has no effect on strings triggered by the serial interface.
The setting of this command is NOT stored permanently. Any system reset (the converter is
powered up or the rotary switch is turned) implicitly executes !0. So, if the ! command is not
given explicitly, strings are programmed to be triggered by any MIDI channel. The MIDI
channel, which was programmed into a string, is stored permanently together with the string.
9

The optionally applicable command % (details see below) sets a bit mask, which restricts
transmission of programmed strings to certain messages or data types.
Strings are not deleted by this command and are available again when the corresponding bit
is set
Immediately following the command code % a byte has to be entered as parameter, where
each bit has a special meaning. This parameter is stored permanently and reactivated during
power up. At delivey the parameter is preset to 255 (hexFF), i.e. all individual filters are
set to "pass", only NOTE OFF and velocity=0 are blocked.
Bit0 cleared: no strings are triggered by the serial interface
Bit1 cleared: no strings are triggered by NOTE ON
Bit2 cleared: no strings are triggered by POLY KEY PRESSURE
Bit3 cleared: no strings are triggered by CONTROL CHANGE
Bit5 cleared: no strings are triggered by PROGRAM CHANGE and CHANNEL PRESSURE
Bit5 cleared: no strings are triggered by PITCH WHEEL N
Bit6 cleared: all strings triggered by MIDI messages are not sent from the serial interface,
but instead from MIDI OUT (overwrites the direction individually set by !). Serially
triggered messages are not influenced by this bit.
Bit7 set: NOTE ON messages with velocity=0 and all NOTE OFF messages are ignored
(even applied on standard conversions described above)
Bit7cleared: NOTE ON messages with velocity=0 are enabled to trigger strings.
The ASCII text command interpreter: (rotary switch position F)
This command interpreter is used to enter ("program") the strings introduced above.
Furthermore it provides the means for interactive operation of the MIDI interface: send MIDI
messages and poll the MIDI IN buffer in ASCII text format. The built-in I/O resources can be
handled, the serial port can be configured (baud rate, RTS/CTS handshake) and system
parameters, which are relevant for other rotary switch positions may be entered here.
This command interpreter has an easier syntax than the programmable command interpreter
which is described below. It immediately reacts on commands via serial interface but cannot
be used for standalone operation.
Setting the baud rate is described above together with "Installation and first operation".
General structure of commands:
CommandCode Parameter [CmdCode Parameter ]
--- Some command codes are used to select certain I/O methods ("devices" = virtual instruments), these
are the commands : (colon) , ; (semikolon), S, M, @ ,U, K, J, X, G , W and {
--- Other command codes define the action which has to be executed with the previously selected
or implicitly determined device, these are R, L, H, P, Z , T , [ and ].
--- Last not least there is a third kind of command codes which affect the general system
behaviour, examples of these include: N , ! . ? , % , & , $ and Y.
Every command is executed as soon as the necessary number of ASCII characters is
entered and interpreted. Input of any number is automatically finished as soon as the
maximum number of digits - context dependent - is entered. Numbers shorter than
10

maximum are finished by starting the next command (input of a command letter) or when
is entered or when the number is filled up to its max. length with leading zeroes.
All ASCII characters are interpreted case independent. Commands entered in lower case
letters are internally converted into upper case. For this reason all command codes are
written upper case in this manual.
Command lines are terminated with (hexD,dec13). This starts immediate
execution of the previous command and reorganisation of internal structures of the command
interpreter. Though not absolutely necessary, for maximum stability a should be entered
occasionally. (hexA,dec10) is ignored. This must be taken into account when configuring
application programs. Spaces (hex20,dec32) are ignored, too and can be used for better readability.
If a typing error has happend, the pending command should be erased with a keystroke.
"Backspace" is out of action.
Parameters (i.e. numeric values) are always entered in conformance with the active number base
(decimal or hex). After the number base is set to hex with the "$" command, hex numbers are NOT entered
with a preceding $ sign.
Any response to the host controller (PC) is done in the active number base. Hex numbers are sent with a
leading $ sign.
Feedback response:
The Converter does not "echo" commands. If you prefer echoes, activate "local echo" at your terminal.
Every command line which has been interpreted correctyafter and terminated with is acknowledged
with a = hexD, decimal 13 .
If a command cannot be interpreted (usually due to a syntax error) the box echoes a '?' plus . If additional commands were already entered, they are lost.
The Converter sends polled data output immediately after the command (R , U , ? , ; , @ ).
Every requested message is terminated with a . This may be useful for control
software to detect the end of a syntactic set of data.
Ready prompt after power on or reset:
'MIDI RS-232/RS-422 Converter v4.xx'
This message is sent automatically after power on or after reset of the DMX GenIO. Repeated
spontaneous output of this message may be a hint for unstable power supply or extreme immission of
electromagnetic radiation.
Short reference of all ASCII commands (detailled descriptions below)
:nN (colon) program string no. n (n=0-127) for NOTE ON trigger p.12
:nK (colon) program string no. n (n=0-127) for CONTROL CHANGE trigger p.12
:nP (colon) program string no. n (n=0-127) for PROGRAM CHANGE trigger p.12
:no (colon)program string no. n (n=0-127) to be triggered by RS-232/RS-422 character p.12
(o is formally written lower case to be better distingueshed form zero. Is internally converted into upper case)
;nN (semicolon) read / check string no. n (n=0-127) for NOTE ON p.13
;nK (semicolon) read / check string no. n (n=0-127) for CONTROL CHANGE p.13
;nP (semicolon) read / check string no. n (n=0-127) for PROGRAM CHANGE p.13
;no (semicolon) read / check string no. n (n=0-127) for RS-232/RS-422 p.13
%n save bit mask n permanently (message filter for trigger of string transmission) p.14
!n set MIDI channel n (n=0-16) as trigger filter into string p.15
Nn set MIDI channel n (n=1-16)for transformation byte �� MIDI message p.15
$ from now parameters and numerical feedback in HEX p.15
& from now parameters and numerical feedbackin DECIMAL p.15
Sn transmit string no. n (n=0 to 127) from MIDI OUT p.16
11

Mn transmit a single byte n from MIDI OUT p.16
@ read and flush MIDI IN receive buffer in ASCII text format p.16
Un poll analog input no. n (n=0 to3) p.16
KnZ configure digital I/O no.n as high impedance input (n=0 to 3) p.16/17
KnP configure digital I/O no.n as input with pull-up resistor (n=0 to 3) p.16/17
KnL configure digital I/O no.n as output with LOW level (n=0 to 5) p.16/17
KnH configure digital I/O no.n as output with HIGH level (n=0 to 5) p.16/17
KnR poll level of digital I/O or MOS transistor switch (n=0 to 5) p.17
KCR poll all digital I/O collectively as number p.16/17
Yn set time constant n for debouncing of digital I/O (n=1 to 255 in ms) p.17
JR poll pulse counter at I/O no- 0 p.18
XR poll encoder counter at I/O no. 0 p.18
JZ reset both counters at I/O no. 0 p.18
WiHn start PWM at OUT (transistor switch) no. i = 4 or 5 with high phase n p.18
GTn set total period and start frequency generator at OUT (transistor switch) no.5 p.19
GHn set high phase of frequency generator at OUT (transistor switch)no.5 p.19
Qn activate/deactivate RTS/CTS handshake p.19
{ ] save all stored strings and system parameters to PC by XMODEM protocol p.20
{ [ upload a system backup from PC by XMODEM protocol p.20
? send all relevant system parameters as ASCII text string via serial interface p.20
~ ~ configure baud rate to MIDI (31250 bit/s) p.21
| reset all I/O and configuration to default values p.21
enter ("program") a string and store it:
: N
The command code is a colon followed by the 1st data byte of the triggering MIDI message
(note pitch 0-127 / hex7F) terminated by letter N.
: K
The command code is a colon followed by the 1st data byte of the triggering MIDI message
(e.g. controller number 0-127 / hex7F) terminated by letter K.
: P
The command code is a colon followed by the 1st data byte of the triggering MIDI message
(z.B.Programm Nummer 0-127 / hex7F) terminated by letter P.
: o
The command code is a colon followed by the serial byte, which triggers the string (0-127 /
hex7F) terminated by letter o.
Next the string is entered as text. The string is terminated and stored permanently by
quotation marks " (ASCII code hex22). The quotation marks do not become part of the
string, of course.
Examples: :30NHello World" :65o\B0\07\7F"
"Printable" characters (i.e. all characters which can be entered directly with a standard PC
keyboard, ASCII code range hex20 to hex7E) are typed directly.
To enter any byte value else (control codes, contry specific letters) first a backslash \ (ASCII
Code hex 5C) is typed, followed by the desired ASCII code as a 2 digit hex number in text
12

epresentation. For example, a "new line" would be entered as \0d\0a. No leading or trailing
SPACEs may be added, they would be contained in the stored string.
The third "special key" is the backspace key (ASCII code 08), which may be used to delete
and rewrite parts of the string before storage.
If any of these special letters shall be stored in the string instead of beeing used to format the
string, but, it has to be entered by means of the backslash representation:
backslash \ as part of the string: type \5c
quotation marks "as part of the string: type \22
backspace as part of the string: type \08
Mouse operations, cursor keys and special function keys F1 to F12 are not detected or
evaluated.
Every entered letter is "echoed" via RS-232/RS-422 . "Printable" letters are returned 1:1, any
else comes in backslash/text representation as described above. if a printable letter was
entered by backslash representation, it will be returned as plain letter. This way, input of \40
would be echoed as @ .
As soon as the string is terminated by quotation marks, it is permanently stored in the
Converter memory. Any string can be deleted or overwritten at any time (up to10.000 times).
"Editing" is no possible, however.
A string is deleted by entry of an empty string, i.e. the quotation marks follow directly after
the command code : N". Now the string does not contain text and has the
length zero. This configuration is identical with the unprogrammed state at delivery.
Check a string / display it for test:
The command code is a semicolon followed by the 1st data byte of the triggering MIDI
message (note pitch 0-127 / hex7F) terminated by letter N.
; K
The command code is a semicolon followed by the 1st data byte of the triggering MIDI
message (e.g. controller number 0-127 / hex7F) terminated by letter K.
; P
The command code is a semicolon followed by the 1st data byte of the triggering MIDI
message (z.B.Programm Nummer 0-127 / hex7F) terminated by letter P.
First the count of stored characters is returned, next the letter ! with the corresponding MIDI
channel, followed by the string in readable text form as described above as echo of string
entry.
; o
The command code is a semicolon followed by the serial byte, which triggers the string (0-
127 / hex7F) terminated by letter o.
First the count of stored characters is returned, followed by the string in readable text form as
described above as echo of string entry.
13

Please note: String output using backslash representation simply is a readable "interpretation" of the
previously generared memory content. Every byte is actually stored in raw binary format. When the string is
transmitted in "normal operation" the raw binary format is sent, of course.
%
The bit mask blocks specific messages from triggerering transmission of strings:
Immediately following the command code % a byte has to be entered as parameter, where
each bit has a special meaning. This parameter is stored permanently and reactivated during
power up. At delivery the parameter is preset to 255 (hexFF), i.e. all individual filters are
set to "pass", only NOTE OFF and velocity=0 are blocked.
Bit0 cleared: no strings are triggered by the serial interface
Bit1 cleared: no strings are triggered by NOTE ON
Bit2 cleared: no strings are triggered by POLY KEY PRESSURE
Bit3 cleared: no strings are triggered by CONTROL CHANGE
Bit5 cleared: no strings are triggered by PROGRAM CHANGE and CHANNEL PRESSURE
Bit5 cleared: no strings are triggered by PITCH WHEEL N
Bit6 cleared: all strings triggered by MIDI messages are not sent from the serial interface,
but instead from MIDI OUT (overwrites the direction individually set by !). Serially
triggered messages are not influenced by this bit.
Bit7 set: NOTE ON messages with velocity=0 and all NOTE OFF messages are ignored
(even applied on standard conversions described above)
Bit7cleared: NOTE ON messages with velocity=0 are enabled to trigger strings.
Comment: This setting is stored permanently and automatically restored at next microcontroller reset. The
strings are not deleted by the % command and are active again after the corresponding bit is set. The bit mask
is only effective in rotary switch positions 7 to C, for the direction MIDI ���� string in positions 5 and 6 too.
Immediately after the command code % the mask byte is entered as parameter, each bit has a specific effect.
At delivery parameter value 255 (hexFF) is preset, i.e. any individually controlled filter is "transparent" at
delivery, only NOTE OFF and velocity=0 are blocked.
How to create the bit mask: Even without detailled knowledge of information science it is possible to combine
the individual bits to the mask byte by addition. Every set bit is represented by a byte, which is equivalent to its
"weight". For each bit which shall be set, its weight byte is added to get the mask byte. To clear a bit, its
weight is subtracted from the mask byte. The same byte may only added or subtracted once, of course ! Due
to the special construction of the weights, no "carry" or "borrow" happens during this operation.
bit number weight hexadec. weight decimal
bit 0 1 1
bit 1 2 2
bit 2 4 4
bit 3 8 8
bit 4 10 16
bit 5 20 32
bit 6 40 64
bit 7 80 128
Example: Only strings programmed for NOTE ON (except velocity=0) and for serial bytes shall be
triggered. To achieve this, bit0, bit1 and bit7 have to be added:
hexadecimal 1 + 2 + 80 = hex83 and the same decimal: 1 + 2 + 128 = 131
14

! (don't confuse with command N )
set MIDI channel (0 to 16) as filter when programming a string
! 0 switches filtering OFF, i.e. any MIDI channel will trigger.
Comment: The MIDI channel is entered in the same format, which is commonly used in manuals and
MIDI text books. A MIDI message will trigger, if the channel is coded in its status byte by one less
(0-15/hexF). The command !0 causes the string to be triggered independently of the MIDI channel.
The MIDI channel filter selected by command ! (0-16) will be stored in any subsequently programmed
string, until another channel gets selected by a new ! - command.
This parameter is not stored permanently. After a system seset (turning the switch or switch power
on) the parameter is reset to 0. So, by default all strings are programmed to be triggered by any
MIDI channel.
In contrast to commmand N, the command ! is only effective at rotary switch position F, while strings are
programmed. But the programmed channel filter is active when the string is to be triggered (pos. 5 to C).
Example: !1:30Na"!2:31Nb" causes, that after a reception of a NOTE ON message at channel 1
with tone pitch 30 the byte a (ASCII code decimal97/hex 61) will be transmitted from the serial interface
wird and after reception of a NOTE ON message at channel 2 with tone pitch 31 the byte b (ASCII Code
dezimal98/hex 62) will be transmitted.
N (don't confuse with command ! )
--- During a transformation byte���� MIDI message the MIDI channel (1 to 16) will
be inserted into the transmitted MIDI message
--- During a transformation MIDI message ���� byte exclusively received MIDI
messages with this channel will be transmitted from the serial interface. (This
only applies for the standard transformation. For programmed strings, the MIDI
channel is applied, which was stored with command !. Transmission of programmed
strings has priority before standard transformation)
Comment: The MIDI channel is entered in the same format, which is commonly used in manuals and
MIDI text books. In MIDI messages always the channel is coded or filtered by one less (0-15/hexF).
This system parameter is stored permanently and automatically restored after a system reset
(turning the rotary switch or switch power on) .
Example: N1 at rotary switch positions 7 to C transmission or filtering of status bytes hex90 (Note
On), hexB0 (Control Change), hexC0 (Progr.Change) etc. is performed.
$ (no parameter)
Set number base to hexadecimal
Comment: All following parameter values of all commands are interpreted as hexadecimal numbers
and number output is hexadecimal. This behavious remains active until the number base is set to
decimal by command &.
All hexadecimal numbers messaged from the serial interface are signed with a prefix "$".
& (no parameter)
Set number base to decimal
Comment: All following parameter values of all commands are interpreted as decimal numbers and
number output is decimal. This behavious remains active until the number base is set to hexadecimal by
command $.
All decimal numbers messaged from the serial interface come without specifier symbol.
15

S
transmit programmed string no. 0 to127 from MIDI OUT
Comment: Please keep notice of the following difference: Primarily strings are programmed with the
command interpreter at rotary switch position F, to be triggered by the corresponding serial byte at
rotary swith positions 7 to C. When the switch is at position F or E, reception of the corresponding byte
will not trigger the string. .
Command S however, causes immediate transmission of the corresponding string at rotary
switch position F.
Example: S65 causes transmission of the string which was stored to be triggered by letter A.
M
transmit the byte which follows in ASCII text representation immediately from
MIDI OUT
Example: serial text input $M90M30&M64 causes transmission of a NOTE ON messaga at MIDI
channel 1 for note c with standard velocity decimal 64.
@ (no parameter)
polls the MIDI IN receive buffer and transmits the content ASCII text via the
serial interface. Number base as set by command & or $ .
Comment: The output starts with letter @, followed by the number of bytes which is actually stored in
the buffer (always decimal format) and a colon. Next follow max 16 eldest bytes from the buffer in
the actual number base, which are deleted from the buffer, too. If the buffer contains more bytes,
the command has to be given repeatedly to extract all bytes and flush the buffer.
Example of a typical output: @3:$90 $30 $40 . Signals that a NOTE ON was
received, transmits it via RS-232/RS-422 and deletes it from the buffer.
U
Read analog input via serial interface.
Parameter: input number (range 0 to 7)
The result comes as 10 bit number 0 to 1023
Example: U3 causes immediate readout of the actual voltage of input no.3.
K < number >
Select a digital (“Kombi“) I/O for subsequent action.
Parameter: input number (range 0 to 3, with restricted effect 4 and 5)
Example: K3 makes subsequent action commands effect on digital I/O no.3 (device selection but no
action yet),
to be completed: K3R causes immediate readout and message of the actual logic level (physical line
level is read independent if configured as input or output)
K5H configures transistor switch K5 to ON state.
Special case: KCR reads the logic levels of all I/O as one data word. Every bit of this
data word is equal to the logic level of the respective I/O - number.
I/O no.0 adds to the number with weight 1 and I/O no.5 adds with weight 32
(in general: I/O no. n adds with weight 2 n )
16

Example: If all digital I/O are configured as inputs with pull up resistors and the transistor switches
are set to OFF (= state of delivery without external components), then the command KCR will
message:”KC:15” or when hex numbers are active: “KC:$F”.
L (no parameter)
configures the previously selected digital I/O as output with LOW level
Example: K3L
H (no parameter)
configures the previously selected digital I/O as output with HIGH level
Alternative meaning: GHn sets the high portion of the square wave generator
P (no parameter)
sets the previously selected digital I/O as input with pull-up resistor
Comment: The pull-up resistor (ca. 20-30 kKiloohm) connects the input internally with +5 Volt, as a result
high level is read when no external components are connected. External signals may pull down this
level. This kind of preset is rather insensitive to electric noise.
Z (no parameter)
sets the previously selected digital I/O as input with high impedance ("hi Z")
Alternative meaning: JZ reset the pulse counter and the encoder counter
R(no parameter)
“READ” = command to read (poll) an input value or OUT level
Individual digital I/O are always reported debounced. See command Y.
The command KDR however reads the input states immediately and directly - without noise filtering-
- and therefore it is best suitable for very fast evaluation.
Comment: The answer is sent in the following ASCII format:
--- Repetition of the polled I/O "device"
--- if adequate: I/O number
--- colon
--- result as number in ASCII text representation
---
Examples: K3R messages for instance K3:0
KCR messages for instance KC:$A
XRmessages for instance X:25478
Y )
sets the time constant to debounce readout of digital I/O (ca. in milliseconds)
Parameter: time delay between two samples and compares of the logic levels of the
digitalI/O. in milliseconds
17

The permanent sampling of input levels and comparison with their previous values is
automatically performed as a background process. According to the intended application it
makes sense to perform this comparison in short time intervals or with a certain delay. For relay
contacts 10 milliseconds most times is an appropriate time interval, but to debounce simple
pushbuttons 40-100 milliseconds are preferable.
The default setting is 40 milliseconds.
Because the sampling process is not synchronized with the changes of external signals, it takes
at least one and up to two periods of the sampling timer to recognize a debounced input change
reliably. Pulses shorter than two periods may be disregarded.
Example: Y10 sets the I/O sampling periode to 10 ms
JR (no parameter)
Poll pulse counter at I/O no. 0.
Comment: Pulse counter and encoder counter use separate memory cells, so they can be read
independently. The reset command however influences both counters in common.
JZ (no parameter)
Reset pulse copunter and encoder counter at I/O no. 0
Comment: The reset command always influences both counters in common.
XR (no parameter)
Read encoder counter at I/O no. 0
(the direction of rotation
= direction of count is determined by the logic level at I/O no.1)
Comment: whereas the the pulse counter is increased at any high-to-low level change at I/O no. 0,
the encoder counter checks the actual level at I/O no.1. If "high", the counter is incremented, if "low" the
encoder counter is decremented
1
W4H
Activates transistor switch no. 4 as pulse width modulator. In its standard setup the
pulse width modulator words with a constant frequency of 15686 Hz and is adjustable with
steps of 8 bit resolution (i.e. within 255 = hex FF steps).
Parameter: high portion of the pulse shape at I/O no.4.
expressed in percent: 100 x / 255
Switch this pulse width modulator OFF with any command applied to transistor
OUT no. 4 (K4L, K45H).
Comment: Have a look at appendix A for more complex options of PWM setting.
Example: W5H128 generates a square wave at transistor no.4 (open drain) with 50% high portion
W5H
Activates transistor switch no. 5 as pulse width modulator. In its standard setup the
pulse width modulator words with a constant frequency of 3910 Hz and is adjustable with
steps of 10 bit resolution (i.e. within 1023 = hex3FF steps).
18

Parameter: high portion of the pulse shape at I/O no.0.
expressed in percent: 100 x / 1023
Switch this pulse width modulator OFF with any command applied to transistor
OUT no. 5 (K5L, K5H) or with any command to start the square wave generator.
Comment: Have a look at appendix A for more complex options of PWM setting.
Example: W5H256 generates a square wave at transistor no.5 (open drain) with 25% high portion
GT
Activates digital I/O no. 5 as a programmable square wave generator.
Parameter: Total period of the output sqare wave as a multiple of about 32
microseconds. Therefore the max. Frequency is about 15,6 Kilohertz (GH=1,GT=2).
Accepted parameters are in the range 1 to 65535 (hexFFFF). The maximum
parameter sets the minimum frequency, which is about 1 Hz.
Switch the frequency generator OFF with any 'K' - command applied to digital I/O
no. 5 (K5L, K5H) or with any command which starts the pulse width modulator W5.
Comment: The square wave generator is always started with a sequence of TWO commands:
Before the square wave generator can be started, the duration of the high period has to be
entered with the command 'GH'. Else unpredictable behaviour has to be expected. But when the
square wave generator is active, total period and high period can be changed independently with
immediate effect. Of course, the total period must always be bigger than the high period!
Example: GH100GT200
GH
Preselection of the high period for I/O no. 5 as square wave generator.
Q1
Parameter: Duration of the high period of the output sqare wave as a multiple of about
32 microseconds. Accepted parameters are in the range 1 to 65534 (hexFFFE).
See comment at "GT" command above
Comment: Before the square wave generator may be started, the duration of the high period
has to be initialized with this command GH. While the square wave generator is active, total period
and high period can be changed independently with immediate effect. Of course, the total period
must always be bigger than the high period!
Example: GH2GT$FFF
switch RTS/CTS Handshake ON
Q0
switch RTS/CTS Handshake OFF
19

{ ] (no parameter)
Initiates "download" of the complete nonvolatile memory (all strings and permanently
stored system configuration) to a PC via RS-232 using the "XMODEM CRC" protocol
Comment: This command allows to make a backup of possibly expensively programmed strings
To avoid accidental start of this command, both command bytes have to be entered in immediate
sequence.
On the computer which is used for the backup a software has to be installed and started which is able to
perform the transfer als a sequence of defined data packets using the XMODEM CRCprotocol.
Applicable transfer software is for example "Hyperterminal", which is combined with a terminal software
to perform any ASCII operation of the Converter too, especially rotary switch positions E and F.
First the command sequence { ] has to be entered. Then a message is sent back to the controlling PC
that the XMODEM CRC 'Receive' function should be started. Now the user opens a corresponding
dialog at the XMODEM software where the name of the backup file is entered. The Converter remains
waiting for max 100 seconds while these steps are performed on the PC. After this is finished the PC
initiates and controls the download. Depending on the baud rate, the download takes about 1 minute.
{ [ (no parameter)
Initiates "upload" of a previously stored backup to the nonvolatile memory (all
programmed string and permanently stored system configuration) from a PC via RS-
232 using the "XMODEM CRC" protocol
Comment: On the controlling PC a software has to be started, which is able to transfer the backup as
a sequence of defined data packets using the "XMODEM CRC" protocol. This may be attractive to
exchange different sets of "programmed strings"
To avoid accidental start of this command, both command bytes have to be entered in immediate
sequence.
It is exclusively possible to upload a backup from a MIDI RS-232/RS-422 Converter, not from other
similar Cinetix products. Under certain conditions after a hardware update (microcontroller module) a
backup made with a previous version may be uploaded - but under some conditions it may be
impossible. Contact Cinetix service to check if this is possible in a specific case.
First the command sequence { [ has to be entered. Then a message is sent back to the controlling PC
that the XMODEM CRC 'Send' function should be started. Further guide see comment of the
complementary download command { ].
? (no parameter)
send all relevant system parameters as ASCII text string via serial interface
Comment: The returned arguments describe following system features and the preceeding letters
are identical with the respective command codes:
KC: reads the actual levels of digital I/O no. 0 - 3 and digital OUT 4 and 5.
o: data direction of digital I/O no. 0 - 3 as bit mask: bit=0: input, bit=1: output
Y: debounce time constand of the digital I/O in milliseconds
Q: RTS/CTS handshake: 0=OFF, 1=ON
@: actually stored number of bytes in the MIDI IN receive buffer
N: configured MIDI channel for standard transformation serial byte �� MIDI message
!: MIDI channel to be inserted into programmed strings
%: bit mask for filtered trigger of programmed strings
Example of a typical message:
KC:15 o:0 Y:40 Q:0 @:0 N:1 !:0 %:255
20

~ ~ (no parameter)
Sets the baud rate of the RS-232/RS-422 interface to MIDI (31250 Bit/s)
Comment: the 'tilde' character has to be entered twice in immediate sequence. The changed baud
rate wird is stored permanently, but not active before the next system reset (power on or turn of the
rotary switch).
| (no parameter)
"clear all memory": All buffers and system parameters are reset to their default values:
--- number base "decimal"
--- the MIDI channel for filtering of programmed strings (command !) is reset to 0 (= "all MIDI channels").
--- All digital I/O are configured as ínput with pull-up resistor.
--- digitalen OUT K4 and K5 are switched to low level (transistors OFF).
--- All pulse generators are switched OFF
The setting of the serial interface, the bit mask to filter trigger of programmed strings,
the MIDI channel to be used for transformation serial byte �� MIDI vessage
and all programmed strings remain unchanged.
Merge- and Through-Box: (rotary switch position D) (new from July 2011)
In this mode of operation any MIDI channel messages and MIDI System Exclusive messages
received at MIDI IN as well as those received at the serial interface are merged together
maintaining correct integrity of messages (i.e. no MIDI message is interrupted or divided by
another one from the other input). The resulting multiplexed signal is retransmitted
simultaneously from MIDI OUT and from the serial interface. Running State is compensated
(missing status bytes are inserted automatically to avoid confusion when different messages
are merged).
The baud rate of the serial interface is configurable, especially MIDI baud rate can be
selected.
By means of this technique for example MIDI messages transmitted from a media controller
in standard PC baudrate can be copied into an existing stream of MIDI data. Or in
combination with a "RS-422 Expander for MIDI signals" two spatially wide separated MIDIsources
may be merged together.
With some rather simple external hardware the RS-422 interface (and with some restrictions the RS-232
interface too) can be modified to become a standard MIDI interface. See appendix B and
"www.cinetix.de/interface/tiptrix/".
21

The programmable command interpreter:
Due to the complexity of this item only the most essential features can be indicated here. The complete
documentation of the alternative programmable command interpreter is published at the website "www.ascontrol.de"
or at the supplied CD-ROM.
The programmable Command interpreter is only activated at position 0 of the rotary
switch. Setup of the serial baud rate see "Installation and first operation" above.
Operation and programming of the command interpreter are performed generally via the
serial RS-232/RS-422 interface. But with a suitable user program ist is possible, to run
fuctions of the interpreter by use of MIDI messages.
Apart from some special functions – which offer themselves for a device with MIDI interface –
user programming is performed by means of a syntax, which roughly follows a very simplified
"C" or "Java". It is implemented as a virtual stack engine that is completely created in fast
assembly code and so takes most out of the CPU power of the embedded microcontroller.
Differing from similar projects compilation of user projects takes place directly in the AS-
Control interpreter and not in advance with a special tool on the host PC.
Simplifications and modifications of the C syntax were made eyspecially to reduce the need
for memory and to provide a tool for efficient interactive and experimental handling. So there
are no function prototypes and no mandatory "main" function. The interpreter runs
permanently in the "main" loop: according to the situatiuon, it is set frome the interpreting into
compiling state and after finishing this job it jumps back into interpreting/ executing state.
Any function can be called from the controlling software (a terminal or industrial PLC, e.g.) at
any time for its own - or it can be called by any function else during runtime .
Some simple examples. For detailled understanding however, you are referred to the
detailled documentation:
--- With the command "ops" a list of internal operators of the interpreter plus
actually stored user-programmed funtions is listed via serial port. Internally all
names of operators and functions are handled exclusively in upper case letters.
But input is possible case independent - differering from 'C'.
--- Operators and previously programmed user functions may be composed
spontaneously to immediate operations via terminal input,
example: " p ( 2 + 3 ) " sends the resulting text '5' to the terminal.
This demonstrates an essential restriction compared with a C-compiler usually running on a PC:
every single syntactic element ("token") has to be separated with a SPACE.
--- The same operationcan be compiled permanently as a user function as follows:
" : sum p ( 2 + 3 ) ret "
and from now an be called and executed with the phrase "sum " .
The same procedure is applicable to I/O processes. For example the phrase
" mtx3 (0xb0, 7 , u1 & 127 ) "
evaluates one of the analog inputs as a MIDI volume control. With some
additional programming work this can be compiled as an infinte loop within a
user function or even as a background task..
--- A set of user functions may be built "bottom-up" to more complex functions.
--- this way chains of MIDI messages can be triggered with simple ASCII commands
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or by sensor input. Vice versa complex serial data messages may be triggered
by a simple MIDI message.
--- By use of the operator "autoexe" a user programmed function can be started
automatically at system start. This provides a method for reset-proof
standalone applications.
Additionally at low system level a filter for MIDI channel messages is incorporated.
MIDI channel messages which are filed arbitrarily into the data stream received at MIDI IN
are picked out and put into a special buffer. They can be evaluated asynchroneously by the
small standalone operating system. To get them clearly separated from other ASCII text it is
strongly recommended not to send MIDI channel messages in running state! This way it
is possible, for instance, to control a program flow with an external MIDI keyboard and to
combine such an input with the states of the I/O lines. For this purpose the following special
commands are implemented: MCHECK, GETMSG, DROPMSG, STATUS, MDAT1, MDAT2.
MCHECK is equivalent to "kbhit" in C-programming. Instead of a TRUE flag it returns the
status byte of the MIDI message which would be read next out of the buffer (= eldest
available in the queue), but leaves the message in the buffer.
GETMSG gets the next channel message out of the buffer (or waits infinitely for the next one
to arrive). The components of this message are stored into the respective system variables
STATUS, MDAT1 and MDAT2 – which subsequently can be read with commands of the
same name. They are not deleted before the next MIDI message is taken out of the buffer
with a GETMSG command.
DROPMSG deletes the eldest channel message out of the buffer. The system variables
described about remain unchanged.
Vice versa an easy to handle set of commands is implemented to format and send all MIDI
channel messages as well as System Exclusive messages. With the command MC the MIDI
channel inserted into MIDI messages may be temporarily modified with respect to the default
setting.
Appendix A:
more complex configuration of the pulse width modulator at I/O no. 4:
this pulse width modulator provides only 8 bit of resolution. The handling of Hi Arg and Low Arg corresponds
with the description for I/O no. 5 below
Hi Arg. (hex) Hi Arg. (dez) base frequency (ca Hz) Low Arg.(hex) Low Arg. (dez)
0 oder 100 256 15682 0 .. FF 0..255
200 512 1960 0 .. FF 0..255
300 768 490 0 .. FF 0..255
400 1024 245 0 .. FF 0..255
500 1280 123 0 .. FF 0..255
600 1536 61 0 .. FF 0..255
700 1792 15 0 .. FF 0..255
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more complex configuration of the pulse width modulator at I/O no. 5:
With the configuration method described in the main part of the manual, the pulse witdth modulators at
transistor outputs no 4 and 5 are quite useful for generation of analog output voltages by means of an
external low pass filter. With the alternatives described as follows other interesting applications become
possible, as drive of RC servo motors.
The concept is understood best when it is regarded in hexadecimal notation. The highest nibble (“Hi-Arg”)b
describes base frequency and resolution, the lower 3 nibbles define the high portion of the generated
square wave. "Thinking decimal"you have tpo add both parts as “strange odd” numbers.
Anyhow: the configuration described in the main part of the manual is identical with the one described here with
Hi Arg hex9000. When the pulse width modulator is started, the Hi-Arg always has to be entered explicitly (apart
from special case cited above). If the Low-Arg shall be modified while the PWM is active, it is sufficient to
set the hHigh-Argument = 0.
Hi Arg. (hex) Hi Arg. (dez) resolution (Bit) base frequency (ca.Hz) Low Arg.(hex) Low Arg. (dez)
1000 4096 8 15686 0 .. FF 0..255
2000 8192 8 1960 0 .. FF 0..255
3000 12288 8 245 0 .. FF 0..255
4000 16384 8 61 0 .. FF 0..255
5000 20480 8 15 0 .. FF 0..255
9000 36864 10 3910 0 .. 3FF 0..1023
A000 40960 10 489 0 .. 3FF 0..1023
B000 45056 10 61 0 .. 3FF 0..1023
C000 49152 10 15 0 .. 3FF 0..1023
D000 53248 10 3.8 0 .. 3FF 0..1023
Appendix B: MIDI interface at the RS-422 interface
* ) the RS-422 driver IC has a certain source resistance. If more than 2 MIDI OUT are connected, the serial
resistor at MIDI OUT should be reduced to 180 Ohm.
Cinetix Medien und Interface GmbH
Gemündenerstr. 27 D-60599 Frankfurt/Main
Fon: +49-69-68 51 05 Fax +49-69-68 600 409
http://www.cinetix.de/interface/
* Right of technical modifications reserved.
* This description is for information only, no product specifications are assured in juridical sense.
* Trademarks and product names cited in this text are property of their respective owners.
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