Serial Communications Instructions; Serial Communications - Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual

Serial Communications Instructions

Example
3-24 Serial Communications Instructions

3-24-1 Serial Communications

Note
972
In this example, IOWR(223) is used to write data.
D
CPU Unit
10 words
This section describes instructions used for serial communications.
Instruction
PROTOCOL MACRO
TRANSMIT
RECEIVE
TRANSMIT VIA SERIAL COMMU-
NICATIONS UNIT
RECEIVE VIA SERIAL COMMU-
NICATIONS UNIT
CHANGE SERIAL PORT SETUP
There are two types of serial communications instruction. The TXD(236),
RXD(235), TXDU(256), and RXDU(255) instructions send and receive data in
no-protocol (custom) communications with an external device. PMCR(260)
sends and receives data using user-defined protocols with an external device.
The difference is shown in the following tables.
1. The TXD(236) and RXD(235) instructions transfer data only through the
CPU Unit's built-in serial port or a serial port on a Serial Communications
Board (Ver. 1.2 or later).
2. The TXDU(256) and RXDU(255) instructions transfer data only through a
Serial Communications Unit (Ver. 1.2 or later).
When CIO 000000 is turned ON, the 10 words in D00100 to
D00109 are written to the Special I/O Unit.
D+1
Number of words
to transfer: 10
The control code (C) varies depending on the Special I/O Unit.
Special I/O Unit (Unit #3)
Mnemonic
PMCR
TXD
RXD
TXDU
RXDU
STUP
Section 3-24
D
Unit number: 3
Function code Page
260 974
236 983
235 993
256 1005
255 1013
237 1021