A-1-21 Serial Communications Instructions - Omron CP1E CPU UNIT SOFTWARE User Manual

A-1-21 Serial Communications Instructions
Instruction Mnemonic
TRANSMIT TXD
RECEIVE RXD
CP1E CPU Unit Software User's Manual(W480)
Variations Symbol/Operand
@
TXD(236)
S
C
N
S: 1st source word
C: Control word
N: Number of bytes
0000 to 0100 hex
(0 to 256 decimal)
@
RXD(235)
D
C
N
D: 1st destination word
C: Control word
N: Number of bytes to store
0000 to 0100 hex
(0 to 256 decimal)
Function
Outputs the specified number of bytes of data without conversion
from the RS-232C port built into the CPU Unit or the serial Option
Board according to the start code and end code specified for
no-protocol mode in the PLC Setup.
C: Control word
15 12 11 8 7 4 3 0
C
Byte order
0: Most significant bytes first
1: Least significant bytes first
RS and ER signal control
0: No RS and ER signal control
1: RS signal control
Always 0
2: ER signal control
3: RS and ER signal control
Serial port specifier
1: CPU Unit's RS-232C port
2: Serial Option Board port
Reads the specified number of bytes of data starting with the
specified first word from the RS-232C port built into the CPU Unit
or the serial Option Board according to the start code and end
code specified for no-protocol mode in the PLC Setup.
C: Control Word
15 12 11 8 7 4 3
C
Always 0
CS and DR signal monitoring
0: No CS and DR signal monitoring
1: CS signal monitoring
2: DR signal monitoring
3: CS and DR signal monitoring.
Serial port specifier
1: CPU Unit's RS-232C port
2: Serial Option Board port
Appendices
0
Byte order
0 Hex: Most significant byte
to least significant byte
1 Hex: Lest significant byte
to most significant byte
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