Omron CS1G/H-CPUxxH Instructions Manual page 916

Network Instructions
Precautions
Examples
Name Address
Communications A203 to
Port Completion A210
Codes
File Memory Opera- A34313
tion Flag
If the Communications Port Enabled Flag is OFF for the port number specified
in C+4, the instruction will be treated as NOP(000) and won't be executed.
The Error Flag will be turned ON in this case.
When data will be transmitted outside of the local network, the user must reg-
ister routing tables in the PLCs (CPU Units) in each network. (Routing tables
indicate the routes to other networks in which destination nodes are con-
nected.)
Refer to the FINS command response codes in the CS/CJ Series Communi-
cations Commands Reference Manual (W342) for details on the completion
codes for network communications.
Only one network instruction may be executed for a communications port at
one time. To ensure that CMND(490) isn't executed while a port is busy, pro-
gram the port's Communications Port Enabled Flag (A20200 to A20207) as a
normally open condition.
Communications port numbers 00 to 07 are shared by the network instruc-
tions and PMCR(260), so CMND(490) cannot be executed simultaneously
with PMCR(260) if the instructions are using the same port number.
Always use one of the Communications Port Enabled Flags (A20200 to
A20207) in an NO input condition and the File Memory Operation Flag
(A34313) in an NC input condition for CMND(490) when send a FINS com-
mand to the local CPU Unit.
Noise and other factors can cause the transmission or response to be cor-
rupted or lost, so we recommend setting the number of retries to a non-zero
value which will cause CMND(490) to be executed again if the response is not
received within the response monitoring time.
The following program section shows an example of sending a FINS com-
mand to another CPU Unit.
When CIO 000000 and A20207 (the Communications Port Enabled Flag for
port 07) are ON, CMND(490) transmits FINS command 0101 (MEMORY
AREA READ) to node number 3. The response is stored in D00200 to
D00211.
The MEMORY AREA READ command reads 10 words from D00010 to
D00019. The response contains the 2-byte command code (0101), the 2-byte
completion code, and then the 10 words of data, for a total of 12 words or 24
bytes.
Operation
These words contain the completion codes for the
corresponding ports (00 to 07) following execu-
tion of a network instruction.
The corresponding word will contain 0000 while
the network instruction is being executed and the
completion code will be written when the instruc-
tion is completed. These words are cleared when
program execution begins.
ON when any FINS command is sent to the local
CPU Unit (even for FINS commands not related
to file memory) or when any of the following
instructions or operations are performed for file
memory.
FREAD(700) or FWRIT(701)
Program overwrite with control bit in memory
Simple backup operation
Section 3-25
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