Omron CJ1W-CLK21-V1 Using the Message Service, SEND/RECV Flags, Name Address Contents Word Bit

Using the Message Service Section 6-3

6-3 Using the Message Service

With SEND, RECV, and CMND, the Network Instruction Enabled Flag and Network Instruction Error Flag are generally written into the program as input conditions, as shown below. Only one instruction can be executed at a time for any given communications port. Exclusive control thus must be incorporated to execute two or more instructions per operating level with C200HX/HG/HE PLCs, nine or more instructions with CS/CJ-series, CVM1, and CV-series PLCs (because CVM1 and CV-series PLCs have eight ports), or two or more instructions with CQM1H-series PLCs.

Execution	Network Instruction	C
condition	Enabled Flag		KEEP A
			Keep instruction
Reset B
	Active Node Flag for
A	destination node
			Operand and
Active Node Flag for			control data cre-
			ation by @MOV
source node			and @XFER
			Communications
			instruction
			@SEND
			@RECV
			@CMND
	Network Instruction
A	Enabled Flag		Startup differ-
			ential
			DIFU B
A	Network Instruction Error Flag
Execution	Network Instruction
	Enabled Flag	A
condition			KEEP C
			Keep instruc-
			tion
Reset D
	(Continues in the same way.)

Turns A ON from beginning to completion of communications instruction.

Creates operand and control data in a given area.

Executes communications instruction.

Creates reset input. (Turns reset B ON after execution of communications instruction.)

In case of Send Error Flag, re-send processing can be executed.

Exclusive control to prevent simultaneous execution:

Establishes exclusive control so that no communications instruction is started before the previous one has been completed.

SEND/RECV Flags

CS/CJ-series PLCs

Name		Address	Contents
	Word	Bit
Network Instruc-	A202	Port number corresponds	0: Execution not enabled (executing)
tion Enabled Flag		to bit number, i.e., port 0:	1: Execution enabled (not executing)
		bit 00, port 1: bit 01, etc.
Network Instruc-	A219	Port number corresponds	0: Normal end
tion Error Flag		to bit number plus 8, i.e.,	1: Abnormal end
		port 0: bit 08, port 1: bit 09,
		etc.

Note With CS/CJ-series PLCs, ports 0 to 7 are also used for executing the PMCR (Protocol Macro) instruction, therefore these flags are used for the 4 instruc- tions, SEND/RECV/CMND/PMCR. When the PMCR command is being exe- cuted, the same port cannot be used for SEND/RECV/CMND instructions.

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