DVP-ES2-EX2-SS2-SA2-SX2-Operation Manual

DVP-ES2/EX2/SS2/SA2/SX2/SE Operation Manual - Programming
3. When data receiving is completed, M1123 will automatically be ON. When data processing on
the received data is completed, M1123 has to be reset (OFF) and the PLC will be ready for
communication again. However, DO NOT continuously execute RST M1123, i.e. it is
suggested to connect the RST M1123 instruction after the drive contact M1123.
M1002
MOV
H86
D1120
Set up communication protocol as
9600, 7, E, 1
SET
M1120
Retain communication protocol
Pulses for
sending request
Pulse
X0
Receiving
completed
M1123
MOV K100 D1129 Set up communication time-out as 100ms
Write transmitting data in advance
SET M1122 Sending request
RS D100 K10 D120 K10
Processing received data
RST M1123 Reset M1123
Program Example 2: COM2 RS-485
Switching between 8-bit mode (M1161 = ON) and 16-bit mode (M1161 = OFF)
8-bit mode:
1. STX (Start of Text) and ETX (End of text) are set up by M1126 and M1130 together with
D1124~D1126. When PLC executed RS instruction, STX and ETX will be sent out
automatically.
2. When M1161 = ON, only the low byte (lower 8 bits) is valid for data communication, i.e. high
byte will be ignored and low byte will be received and transmitted.
M1000
X0
M1161
RS
D100
K4
D120
K7
Sending data: (PLC -> external equipment)
STX D100L D101L D102L D103L ETX1 ETX2
source data register, starting from
the lower 8 bits of D100
length = 4
3-204