Omron I537-E2-01 User Manual page 189

Loopback Test
The loopback test returns command messages directly as response messages without changing the contents to
check the communications between the master and slave. You can set user-defined test code and data values.
The following table shows a message example when performing a loopback test with the slave 1 Inverter.
Command Message
Slave address 01H
Function code 08H
Higher 00H
Test Code
Lower 00H
Higher A5H
Data
Lower 37H
Higher DAH
CRC-16
Lower 8DH
Writing to Multiple Storage Registers
Write the specified data to the registers from the specified addresses. The written data must be consecutive,
starting from the specified address in the command message: Higher 8 bits, then lower 8 bits, in storage regis-
ter address order.
The following table shows an example of a message when forward operation has been set at a frequency refer-
ence of 60.0 Hz in the slave 1 Inverter by the PLC.
Command Message
Slave Address 01H
Function Code 10H
Higher 00H
Start
Address
Lower 01H
Higher 00H
Quantity
Lower 02H
No. of data 04H
Higher 00H
Lead data
Lower 01H
Higher 02H
Next data
Lower 58H
Higher 63H
CRC-16
Lower 39H
Set the number of data specified using command messages as quantity of specified messages x 2. Handle
response messages in the same way.
IMPORTANT
Response Message
(During Normal Operation)
Slave address 01H
Function code 08H
Higher 00H
Test Code
Lower 00H
Higher A5H
Data
Lower 37H
Higher DAH
CRC-16
Lower 8DH
Response Message
(During Normal Operation)
Slave Address 01H
Function Code 10H
Higher 00H
Start
Address
Lower 01H
Higher 00H
Quantity
Lower 02H
Higher 10H
CRC-16
Lower 08H
* No. of data = 2 x (quantity)
Individual Functions
Response Message
(During Error)
Slave address 01H
Function code 89H
Error Code 01H
Higher 86H
CRC-16
Lower 50H
Response Message
(During Error)
Slave Address 01H
Function Code 90H
Error code 02H
Higher CDH
CRC-16
Lower C1H
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