No-Protocol Communications - Omron CJ - PROGRAMMING MANUAL 12-2009 Programming Manual

Serial Communications
6-3-2

No-protocol Communications

Transfer direction
Data transmission
(PLC → External device)
Data reception
(External device → PLC)
Procedure
Set the PLC Setup from a Programming
Device.
(Set the communications to no-protocol
mode and make other communications
settings.)
Power OFF.
Connect the external device to the CPU
Unit's built-in RS-232C port with an RS-
232C cable.
Set the DIP switch on the front of the
CPU Unit. (Turn pin 5 OFF.)
Power ON.
Data transfer
(PLC → External device)
Execute TXD(236).
300
The following table lists the no-protocol communication functions available in
CS/CJ PLCs.
Method Max. amount
Execution of TXD(236)/ 256 bytes
TXDU(256) in the pro-
gram*
Execution of RXD(235)/ 256 bytes
RXDU(255) in the pro-
gram
Note This function is supported by CPU Units with unit version 3.0 or later or Serial
Communications Units/Boards with unit version 1.2 or later.
● Using the CX-Programmer
Refer to the CX-Programmer Operation Manual.
● Using the Programming Console
Set addresses 160, 161, 162, 164, and 165. (Set the no-protocol
communications mode and set the start code, end code, data length
to send/receive, and delay.)
Connect the external device to the Serial
Communications Board with an RS-
232C cable.
Data reception
(External device → PLC)
Execute RXD(235).
Message Frame Formats
Data can be placed between a start code and end code for transmission by
TXD(236) or TXDU(256) and frames with that same format can be received
by RXD(235) or RXDU(255). When transmitting with TXD(236) or TXDU(256),
just the data from I/O memory is transmitted, and when receiving with
RXD(235) or RXDU(255), just the data itself is stored in I/O memory. Up to
256 bytes (including the start and end codes) can be transferred in no-proto-
col mode.
Frame format
of data
Start code
Yes: 00 to FF
No: None
Connect the external device to the Serial
Communications Unit with an RS-232C
cable.
Data transfer
(PLC → External device)
Execute TXDU(256).
Section 6-3
Other
functions
End code
Yes: Send delay
00 to FF or CR+LF time (delay
between exe-
No: None
cution and
sending data
from specified
port): 0 to
99,990 ms
(unit: 10 ms)
---
Power ON.
Data reception
(External device → PLC)
Execute RXDU(255).