Omron CS1G/H-CPUxxH Instructions Manual page 864

Serial Communications Instructions
Instructions
TXD(236)
Any of the following can be used.
and
No Start or End Code
RXD(235)
Data
Only Start Code
Only End Code
Data
PMCR(260)
The following type of frames (messages) can be created
to meet the requirements of the external device.
Header
Communications steps
can be created.
Instructions Mode
TXD(236) No-protocol
and (custom)
RXD(235)
PMCR(260) Protocol macro
serial ports on the Serial Communications Board (CS Series only) or Serial
Communications Unit.
Communications frames
Start and End Code
CR+LF End Code
Data Data
Start and CR+LF End Code
Data
Address
Error check Terminator
I/O memory
Read/write
Serial port built into CPU Unit
CPU Unit
RXD(235)
TXD(236)
Serial Communications Board
Receive
Send
Sends or receives data in one direction only.
A send delay can be set.
Data
Data
Up to 16 steps can be defined for sending
and receiving.
Steps can be changed and retry processing
performed based on responses.
Communications monitoring times can be
set.
Symbols can be read/written for the PLC.
Repeat symbols can be used.
Other.
Communications ports
TXD(236)/
RXD(235)
Serial Communications Unit
(CS Series
only)
Serial Commu-
nications Board
Section 3-24
Function
TXD(236) and RXD(235)
cannot use serial ports on
Serial Communications
Boards or other Units.
Serial Communications Unit
Receive
Send
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