Omron CJ1W-CORT21 Operation Manual page 37

Sending CAN Messages
Message commands are used to define the CAN messages for the User Defined CAN Unit. These
commands define which messages can be send by the Unit, the mode of sending, and the timing for
when messages are sent. Each output message buffer can have one of the three modes SM1, SM2 or
SM3. An output message must have the correct length, being less than or equal to 8.
Mode
SM1
SM2
SM3
 Triggered
In send mode SM1, a rising edge in the Send Triggers area determines that an output message will
be sent. In state ST5, the Unit will evaluate the trigger. In all other states a rising edge in the Send
Triggers area is ignored and messages will not be sent.
 On Change
In send mode SM2, a change in the message content determines that the output message will be
sent. In state ST5, the Unit will evaluate the message content. In all other states message contents
changes are ignored and messages will not be sent.
 Cyclic
In send mode SM3, time determines when an output message is sent. In state ST5, the Unit checks
whether the configured cycle time for the output message has elapsed. As soon as it elapses, the
message is sent. In all other states the time intervals not monitored and no messages are sent.
Additional Information
It is allowed and possible to combine any of the three send modes mentioned above and all
three modes can be active at the same time.
Recieving CAN Messages
The User Defined CAN Unit will process any CAN message it receives. The basic processing is to
retrieve the message identifier from the message and compare it with the identifiers defined for the
Unit. In total there are four different scenarios whenever a message is processed.
CJ-series User Defined CAN Unit Operation Manual for NJ-series CPU Unit (W517)
Name
Triggered Sending an output message is triggered with a bit in the CPU
memory. This bit is located in the Send Triggers area (see 4-2
Unit Configuration and Control).
On Change Sending an output message is triggered as soon as the Unit
detects that the message contents have changed or the mes-
sage length has changed (an incorrect message length > 8 is
not considered a change).
Cyclic Sending an output message is triggered as soon as a specified
time has elapsed.
1 Features and System Configuration
Description
1
1-3