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

3. Instruction Set
Flag Function Action
M1121
Data transmission ready. M1121 = OFF indicates that RS-485 in
COM2 is transmitting
System
sets
M1122
Sending request. Before executing communication instructions,
users need to set M1122 to ON by trigger pulse, so that the data
sending and receiving will be started. When the communication is
completed, PLC will reset M1122 automatically.
User sets,
system
resets
M1123
M1124
M1125
M1126
M1130
M1127
M1128
M1129
Data receiving completed. When data receiving of communication
instructions is completed, M1123 will be ON. Users can process the
received data when M1123 is ON. When data processing is
completed, M1123 has to be reset by users.
Supported communication instructions: RS
Data receiving ready. When M1124 is ON, PLC is ready for data
receiving..
Communication ready status reset. When M1125 is set ON, PLC
resets the communication (transmitting/receiving) ready status.
M1125 has to be reset by users after resetting the communication
ready status.
Set STX/ETX as user-defined or system-defined in RS
communication. For details please refer to the table in point 5.
M1126 only supports RS instruction.
Set STX/ETX as user-defined or system-defined in RS
communication. For details please refer to the table in point 5.
M1130 only supports RS instruction
COM2 (RS-485) data sending/receiving/converting completed. RS
instruction is NOT supported.
Supported communication instructions:
MODRD / MODWR / FWD / REV / STOP / RDST / RSTEF /
MODRW
Transmitting/receiving status indication.
Receiving time out. If users set up time-out value in D1129 and the
data receiving time exceeds the time-out value, M1129 will be set
ON.
System
sets ON
and user
resets
System
sets
User
sets/resets
System
sets and
user resets
System
sets
System
sets and
user resets
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