Omron SYSMAC CJ1W-EIP21 - Manual (Page 265)

239
Sending Explicit Messages Section 9-1
This hexadecimal value is returned to indicate the number of words of data in
the additional status field.
Additional status (response):
The additional status defined in EtherNet/IP is returned. For details, refer to
the description of the
Response Codes in Appendix D CIP Message Commu-
nications .
Service response data (response):
The reception data determined by the service code is returned.
Description
• The CIP UCMM MESSAGE SEND command is used to send an Ether-
Net/IP-defined explicit message to another company’s node and receive a
response.
• Unlike other FINS commands, the destination of a CIP UCMM MESSAGE
SEND command’s control data is the local node’s EtherNet/IP Unit or
built-in EtherNet/IP port, and the actual destination node is specified in
the command’s route path.
• When an EtherNet/IP Unit or built-in EtherNet/IP port receives an explicit
message, it automatically returns a response to the message.
• When specifying the timeout time, the proper values are different for last-
hop and relay-hop methods. With the last-hop method, set the timeout
time for the actual request service processing. With the relay-hop method,
the timeout for the relay path must be added to the timeout time for the
actual request service processing.
In CIP routing, the node/Unit performing the routing subtracts the timeout
time for 1 hop, deletes its own address from the routing information, and
relays the message to the next node/Unit.
Set the following timeout values for command processing.
The maximum number of relay nodes (Units) is 16. If the number is more
than 16, the explicit message send command may time out even if the con-
ditions of network and each node (Unit) are normal. If more than 16 relay
nodes (Units) have been set, a constant time must be specified for the re-
quest service processing timeout time (normally 0000 hex).
• Priority Time Tick and Time Out Ticks =
(5 s × Number of relay nodes/Units) + Request processing timeout
• Message monitoring time ≥ Priority Time Tick and Time Out Ticks
• CMND(490) timeout set value = Message monitoring time
A timeout may occur sooner than the actual set value, depending on the
point where the timeout occurs in the path.
• General status = 01 hex, and Additional status = 0204 hex
A FINS timeout error response (0205 hex) may occur if the CMND(490)
timeout set value or message monitoring time is less than the Priority Time
Tick and Time Out Ticks.
Note 1. For details on the parameters of explicit messages, refer to the EtherNet/
IP and CIP specifications.
2. The Open DeviceNet Vendor Association, Inc. (ODVA) can be contacted at
the following address to obtain copies of the EtherNet/IP and CIP specifi-
cations.
ODVA Headquarters
4220 Varsity Drive, Suite A