Omron CJ1G-CPUxx, Instructions Manual

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Network Instructions Section 3-25
Flags
The following table shows relevant bits and flags in the Auxiliary Area.
Precautions If the Communications Port Enabled Flag is OFF for the port number specified
in C+3, the instruction will be treated as NOP(000) and won’t be executed.
The Error Flag will be turned ON in this case.
When an address in the current bank of the EM Area is specified for D, the
transmitted data will be written to the current EM bank of the destination node.
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 RECV(098) 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 RECV(098) cannot be executed simultaneously
with PMCR(260) if the instructions are using the same port number.
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 RECV(098) to be executed again if the response is not
received within the response monitoring time.
Name Label Operation
Error Flag ER ON if the serial port number specified in C+1 is not within
the range of 00 to 04.
ON if the Communications Port Enabled Flag is OFF for
the communications port number specified in C+3.
OFF in all other cases.
Name Address Operation
Communications
Port Enabled Flag A20200 to
A20207 These flags are turned ON to indicate that net-
work instructions, including PMCR(260) may be
executed for the corresponding ports (00 to 07).
A flag is turned OFF when a network instruction
is being executed for the corresponding port and
turned ON again when the instruction is com-
pleted.
Communications
Port Error Flag A21900 to
A21907 These flags are turned ON to indicate that an
error has occurred at the corresponding ports (00
to 07) during execution of a network instruction.
The flag status is retained until the next network
instruction is executed. The flag will be turned
OFF when the next instruction is executed even if
an error occurred previously.
Communications
Port Completion
Codes A203 to
A210 These words contain the completion codes for
the corresponding ports (00 to 07) following exe-
cution 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.