Omron VARISPEED E7 User Manual page 242

Slave Not Responding
In the following cases, the slave will ignore the write function.
When a communications error (overrun, framing, parity, or CRC-16) is detected in the command message.
•
When the slave address in the command message and the slave address in the Inverter do not match.
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When the gap between two blocks (8 bit) of a message exceeds 24 bits.
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When the command message data length is invalid.
•
Application Precautions
If the slave address specified in the command message is 0, all slaves execute the write function,
but do not return response messages to the master.
IMPORTANT
Self-Diagnosis
The Inverter has a built-in function for self-diagnosing of the serial communication interface circuits. This
function uses the interconnected send/receive terminals and emulates messages.
To perform the self-diagnosis function use the following procedure.
1. Switch ON the Inverter power supply, and set 67 (communications test mode) in parameter H1-05 (Termi-
nal S7 Function Selection).
2. Switch OFF the Inverter power supply.
3. Perform the wiring according to
4. Switch ON the terminating resistance. (Turn ON pin 1 on DIP switch 1.)
5. Switch ON the inverter power supply.
Fig 6.54 Communication Terminals Wiring for Self-Diagnosis
If the serial port is working correctly the Digital Operator displays "PASS" on the display.
If an error occurs, a "CE" (MEMOBUS communications error) alarm will be displayed on the Digital Opera-
tor, the fault digital output will be turned ON and the Inverter operation ready signal will be turned OFF.
Fig 6.54.
Individual Functions
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