YASKAWA CIMR-ACA4011 - Page 248

Individual Functions
6-87
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. Set user-defined test code and data values.
The following table shows a message example when performing a loopback test with the slave 1 MxC.
Writing to Multiple Storage Registers
Write the specified data to each specified storage register from the specified addresses. The written data must
be in the following order in the command message: upper 8 bits, then lower 8 bits, in storage register 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 MxC by the PLC.
Command Message
Response Message
(During Normal Operation)
Response Message
(During Error)
Slave address 01H Slave address 01H Slave address 01H
Function code 08H Function code 08H Function code 89H
Test Code
Upper bit 00H
Test Code
Upper bit 00H Error Code 01H
Lower bit 00H Lower bit 00H
CRC-16
Upper bit 86H
Data
Upper bit A5H
Data
Upper bit A5H Lower bit 50H
Lower bit 37H Lower bit 37H
CRC-16
Upper bit DAH
CRC-16
Upper bit DAH
Lower bit 8DH Lower bit 8DH
Command Message
Response Message
(During Normal Operation)
Response Message
(During Error)
Slave Address 01H Slave Address 01H Slave Address 01H
Function Code 10H Function Code 10H Function Code 90H
Start
Address
Upper bit 00H
Start
Address
Upper bit 00H Error code 02H
Lower bit 01H Lower bit 01H
CRC-16
Upper bit CDH
Quantity
Upper bit 00H
Quantity
Upper bit 00H Lower bit C1H
Lower bit 02H Lower bit 02H
No. of data 04H
CRC-16
Upper bit 10H
Lead data
Upper bit 00H Lower bit 08H
Lower bit 01H
Next data
Upper bit 02H
Lower bit 58H
CRC-16
Upper bit 63H
Lower bit 39H
INFO
Set the number of data specified using command messages as quantity of specified messages × 2. Handle
response messages in the same way.