Omron SYSMAC CJ1W-SCU21-V1, Operation Manual

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Communications Timing Section 9-4
Flag Transitions
9-4-4 Timing of Commands Addressed to a Host Computer
Commands addressed to a host computer are sent at the timing shown in the
following diagrams.
Host Computer Sending Data
Command transmission to the host computer can start even when the port is
receiving a command from the host computer (1). The transmission of a
response to the command from the host computer is postponed until the
transmission of the command to the host computer is completed (2).
When a response is not required from the host computer, the Communica-
tions Port Enabled Flag will turn ON when the command to the host computer
has passed from the CPU Unit to the port.
Communications Port
Enabled Flag
Network communications
instructions
(PMCR(260)/SEND(090)/
RECV(098)/CMND(490))
Communications Port
Error Flag
Communications Port
Completion Code
Instruction 1
being
executed Instruction 2
being
executed Instruction 3
being
executed
End of previous
processing
(Normal end)
(No unit correspond-
ing to unit address)
(Normal end)
Response Required
Host computer Command
Command
Response
Response
Serial Communications
Board/Unit
Communications Port Enabled Flag
Command acknowledged
Command completed
No Response Required
Host computer
Serial Communications
Board/Unit
Command
Command Response
Communications Port Enabled Flag
Command acknowledged Command completed
(1)
(2)
(1)
(2)