Omron SYSMAC CJ1W-EIP21 - Manual (Page 254)

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Communicating between OMRON PLCs Section 8-6
Communications Port
Completion Codes The status of a SEND(090), RECV(098), and CMND(490) instruction after
execution is reflected as a communications port completion code, in one word
(two bytes) of data as shown in the following table. (The value is 0000 during
instruction execution.) The recorded status is saved until execution of the next
instruction.
The meanings of the communications port completion codes are the same as
those for FINS commands and responses. Bits 08 to 15 in the communica-
tions port completion code correspond to the first byte of the response code,
and bits 00 to 07 correspond to the second byte. For details, refer to 14-6
Troubleshooting with FINS Response Codes.
Communications Port Error Flag and Completion Codes CMND(490)
Errors that occur when CMND(490) is used generate a Communications Port
Error Flag and are recorded in a communications port completion code only in
the following cases:
• When a response timeout error has occurred.
• When the number of communications data bytes exceeds the maximum
value for the Unit (i.e., 2,000 bytes for the EtherNet/IP Unit or built-in Eth-
erNet/IP port).
• When the actual number of response bytes is greater than the number of
reception bytes that has been set. (The response is not stored in this
case.)
Errors other than these are recorded in the response codes of the responses
stored from the beginning response storage word onwards. Be careful of
these, because there are no Communications Port Error Flags and they are
not recorded in a communications port completion code.
Timing of Communications Flag Changes
• The Communications Port Enabled Flag remains OFF during communica-
tions and turns ON when they are completed (regardless of whether or
not an error occurs).
• The Communications Port Error Flag retains its status until the next trans-
mission or reception.
• The Communications Port Error Flag turns OFF with the execution of the
next communications instruction even if there was an abnormal comple-
tion.
Word Contents
A203 Communications Port 0 Completion Code
A204 Communications Port 1 Completion Code
A205 Communications Port 2 Completion Code
A206 Communications Port 3 Completion Code
A207 Communications Port 4 Completion Code
A208 Communications Port 5 Completion Code
A209 Communications Port 6 Completion Code
A210 Communications Port 7 Completion Code