C.8 Message Examples
Below are some examples of command and response messages.
u
Reading Drive MEMOBUS/Modbus Register Contents
Using the function code 03H (Read), a maximum of 16 MEMOBUS/Modbus registers can be read out at a time.
The following table shows message examples when reading status signals, error details, data link status, and frequency
references from the slave 2 drive.
Command Message
Response Message (normal)
Response Message (fault)
Slave Address
02H
Slave Address
02H
Slave Address
02H
Function Code
03H
Function Code
03H
Function Code
83H
Starting No.
Upper
00H
Data Quantity
08H
Error Code
03H
Lower
20H
1st storage
register
Upper
00H
CRC-16
Upper
F1H
Data Quantity
Upper
00H
Lower
65H
Lower
31H
Lower
04H
Next storage
register
Upper
00H
CRC-16
Upper
45H
Lower
00H
Lower
F0H
Next storage
register
Upper
00H
Lower
00H
Next storage
register
Upper
01H
Lower
F4H
CRC-16
Upper
AFH
Lower
82H
u
Loopback Test
Function code 08H performs a loopback test that returns a response message with exactly the same content as the command
message. The response message can be used to check communications between the master and slave. User-defined test code
and data values can also be set.
The following table shows a message example when performing a loopback test with the slave 1 drive.
Command Message
Response Message
Slave Address
01H
Slave Address
01H
Function Code
08H
Function Code
08H
Test Code
Upper
00H
Test Code
Upper
00H
Lower
00H
Lower
00H
Data
Upper
A5H
Data
Upper
A5H
Lower
37H
Lower
37H
CRC-16
Upper
DAH
CRC-16
Upper
DAH
Lower
8DH
Lower
8DH
C.8 Message Examples
YASKAWA TOEPYAIUPW01A YASKAWA AC Drive - U1000 iQpump Matrix Drive User Manual
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C
MEMOBUS/Modbus Communications