Omron NX-EC0112, User Manual

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7 SSI Input Units
7 - 26 NX-series Position Interface Units User’s Manual (W524)
SSI Input Units can exchange I/O data (i.e., perform I/O refreshing) with the Controller through the
EtherCAT Coupler Unit.
The status of the data between the Controller and the SSI Input Unit is indicated in the Process Data
Communications Status.
You can assign the Process Data Communications Status as an EtherCAT Coupler Unit device vari-
able.
Refer to the NX-series EtherCAT Coupler Unit User’s Manual (Cat. No. W519) for details on the Pro-
cess Data Communications Status.
The Process Data Communications Status of the SSI Input Unit operates as described below based on
the communications status of the connected SSI encoder.
After an SSI Input Unit starts, it automatically reads the value from the connected SSI encoder and sets
that value as the initial value for the encoder present position.
If communications were successfully performed with the SSI encoder, the SSI Input Unit reads the ini-
tial value and sets the Encoder Present Position. After the value is set, the bit that corresponds to the
SSI Input Unit in the Process Data Communications Status is set.
Then, SSI communications start when the appropriate command is received.
7-6-6 Process Data Communications Status
When Initial Communications with the SSI Encoder Started Normally
Unit initialization Encoder initial value read. Ready for SSI communications command SSI Input Unit operation
Bit in Process Data
Communications Status that
corresponds to SSI Input Unit
Encoder present position 0 Initial value of the encoder present position
Power turned ON or Unit restarted.