Timing Of Commands Addressed To A Host Computer - Omron SYSMAC CS1W-SCB41-V1 Operation Manual

Communications Timing
Flag Transitions
Communications Port
Enabled Flag
Network communications
instructions
(PMCR(260)/SEND(090)/
RECV(098)/CMND(490))
Communications Port
Error Flag
Communications Port
Completion Code
End of previous
processing
9-4-4

Timing of Commands Addressed to a Host Computer

Host Computer Sending Data
Instruction 1 Instruction 2
being
being
executed
executed
(Normal end)
Commands addressed to a host computer are sent at the timing shown in the
following diagrams.
Response Required
Host computer
Serial Communications
Board/Unit
Communications Port Enabled Flag
Command acknowledged
No Response Required
Host computer
Serial Communications
Board/Unit
Communications Port Enabled Flag
Command acknowledged
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.
Instruction 3
being
executed
(No unit correspond-
ing to unit address)
Command Response
Command
(1)
Command
(1)
Command
Command completed
Section 9-4
(Normal end)
(2)
Response
Command completed
(2)
Response
293