YASKAWA CIMR-ACA4011 Instruction Manual page 248

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.
Command Message
Slave address
Function code
Upper bit
Test Code
Lower bit
Upper bit A5H
Data
Lower bit
Upper bit DAH
CRC-16
Lower bit 8DH
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
Slave Address
Function Code
Upper bit
Start
Address
Lower bit
Upper bit
Quantity
Lower bit
No. of data
Upper bit
Lead data
Lower bit
Upper bit
Next data
Lower bit
Upper bit
CRC-16
Lower bit
Set the number of data specified using command messages as quantity of specified messages × 2. Handle
response messages in the same way.
INFO
Response Message
(During Normal Operation)
01H Slave address
08H Function code
00H Upper bit
Test Code
00H Lower bit
Upper bit
Data
37H Lower bit
Upper bit
CRC-16
Lower bit
Response Message
(During Normal Operation)
01H Slave Address
10H Function Code
00H Upper bit
Start
Address
01H Lower bit
00H Upper bit
Quantity
02H Lower bit
04H Upper bit
CRC-16
00H Lower bit
01H
02H
58H
63H
39H
Individual Functions
Response Message
(During Error)
01H Slave address
08H Function code
00H Error Code
00H Upper bit
CRC-16
A5H Lower bit
37H
DAH
8DH
Response Message
(During Error)
01H Slave Address
10H Function Code
00H Error code
01H Upper bit
CRC-16
00H Lower bit
02H
10H
08H
01H
89H
01H
86H
50H
01H
90H
02H
CDH
C1H
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