1039
Network Instructions Section 3-25
Note When SEND(090) is being executed, the contents of S and D are
read and a FINS command for data transmission is composed.
When RECV(098) is being executed, the content of S is read and a
FINS command for data reception is composed.
When CMND(490) is being executed, the content of S is read and the
corresponding FINS command is composed.
3. If the send processing cannot be completed in a the time available in “serial
communications port servicing” period, the processing will be continued in
the next cycle’s serial communications port servicing.
4. When a response is returned, the system performs the following process-
es:
• Refreshes the destination words specified in the Network instruction
with the response data.
• Turns ON the port’s Communications Port Enabled Flag.
• Refreshes the port’s Communications Port Error Flag (A21900 to
A21907) and Communications Port Completion Code (A203 to A210).
3-25-2 About Explicit Message Instructions
Methods for Using Explicit
Message Communications
There are two methods that can be used to send explicit messages from a
PLC.
• Use the CMND(490) to send a FINS command code of 2801 hex
(EXPLICIT MESSAGE SEND).
• Use the following Explicit Message Instructions. (See note.)
Note These instructions are supported only by CS/CJ-series CPU Unit
Ver. 2.0 or later.
Cycle time (First cycle)
END(001) executed.
3. Processing is
divided up over
several cycles.
Cycle time (Second cycle)
Program execution Program execution
1. SEND(090),
RECV(098), or
CMND(490)
executed.
END(001) executed.
I/O refreshing
Peripheral
servicing
Peripheral
servicing
Sends command.
Receives
response.
2. Communications processing
during “serial communications
port servicing” (Composes and
sends FINS command.)
4. Communications processing
during “serial communications
port servicing” (Receives
response.)
I/O refreshing