Omron CVM1-CLK21, Operation Manual

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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
PCs, nine or more instructions with CS/CJ-series, CVM1, and CV-series PCs
(because CVM1 and CV-series PCs have eight ports), or two or more instruc-
tions with CQM1H-series PCs.
SEND/RECV Flags
CS/CJ-series PCs
Note With CS/CJ-series PCs, 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.
Execution
condition
Network Instruc
tion Enabled Flag
KEEP A
Keep instruction
Turns A ON from beginning to completion of
communications instruction.
Reset B
A
Operand and
control data cre
ation by @MOV
and @XFER
Communications
instruction
@SEND
@RECV
@CMND
Creates operand and control data in a given area.
Executes communications instruction.
Network Instruction
Enabled Flag
A Startup differ
ential
DIFU B
Creates reset input. (Turns reset B ON after execution of
communications instruction.)
Network Instruction Error Flag
Network Instruction
Enabled Flag
A
Reset D
In case of Send Error Flag, re-send processing
can be executed.
Establishes exclusive control so that no communications
instruction is started before the previous one has been
completed.
Exclusive control to prevent simultaneous execution:
(Continues in the same way.)
Active Node Flag for
source node
Active Node Flag for
destination node
A
Execution
condition
KEEP C
Keep instruc
tion
C
Name Address Contents
Word Bit
Network Instruc-
tion Enabled Flag A202 Port number corresponds
to bit number, i.e., port 0:
bit 00, port 1: bit 01, etc. 0: Execution not enabled (executing)
1: Execution enabled (not executing)
Network Instruc-
tion Error Flag A219 Port number corresponds
to bit number plus 8, i.e.,
port 0: bit 08, port 1: bit 09,
etc. 0: Normal end
1: Abnormal end