Omron CQM1H-SCB41 Using No-protocol Communications, Transmit TXD-- and Receive RXD

Using No-protocol Communications Section 6-4

6-4 Using No-protocol Communications

6-4-1 TRANSMIT – TXD(––) and RECEIVE – RXD(––)

This section describes using TXD(––) and RXD(––) for no-protocol communica- tions.

TRANSMIT – TXD(––) in No-protocol Mode

TXD(––)

S

C

N

First source word

Control word

Number of bytes

(4 digits BCD, 0000 to 0256)

Control Word: C

1500

0 0

Byte order	0: Most significant bytes first
	1: Least significant bytes first
Not used. (Set to 0.)
Port	0: RS-232C port on CPU Unit
	1: Port 1 on Serial Communications Board
	2: Port 2 on Serial Communications Board

Not used. (Set to 0.)

The specified number of bytes will be read starting from S and transmitted through the specified port.

•Up to 256 bytes of data can be sent each time the instruction is executed.

•The bytes of source data shown below will be sent in the following order.

If most significant bytes first is specified (0): 12345678..

If least significant bytes first is specified (1): 21436587..

MSB LSB

S	1	2
S+1	3	4
S+2	5	6
S+3	7	8

Communications parameters are set in the PC Setup settings for the Serial

Communications Board. Refer to information in the CQM1H Programming

Manual on serial communications and TXD(––) for details.

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