Yaskawa iQpump Controller User Manual - Manual (Page 219)

D.2 Modbus Function Code Details
YASKAWA TM.iQp.06 iQpump Controller User Manual 219
◆ Loopback Test (08H)
The loopback test returns the command message directly as the response message 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 drive.
Table D.4 Function Code 08H Message Example
◆ Write In Several Holding Registers (10H)
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 register address order.
The following table shows an example of a message when a forward run command has been set at a speed command of 60.0 Hz in the
slave 1 drive by the PLC.
Table D.5 Function Code 10H Message Example
IMPORTANT: Set the number of data specified using command messages as quantity of specified messages x 2. Handle response
messages in the same way.
Command Message
Response Message
(During Normal Operation)
Response Message
(During Error)
Slave address 01 H Slave address 01 H Slave address 01 H
Function code 08 H Function code 08 H Function code 89 H
Test Code
Higher 00 H
Test Code
Higher 00 H Error Code 01 H
Lower 00 H Lower 00 H
CRC-16
Higher 86 H
Data
Higher A5 H
Data
Higher A5 H Lower 50 H
Lower 37 H Lower 37 H
CRC-16
Higher DA H
CRC-16
Higher DA H
Lower 8D H Lower 8D H
Command Message
Response Message
(During Normal Operation)
Response Message
(During Error)
Slave Address 01 H Slave Address 01 H Slave Address 01 H
Function Code 10 H Function Code 10 H Function Code 90 H
Start
Address
Higher 00 H Start
Address
Higher 00 H Error code 02 H
Lower 01 H Lower 01 H
CRC-16
Higher CD H
Quantity
Higher 00 H
Quantity
Higher 00 H Lower C1 H
Lower 02 H Lower 02 H
No. of data 04 H
CRC-16
Higher 10 H
Lead data
Higher 00 H Lower 08 H
Lower 01 H
Next data
Higher 02 H
Lower 58 H * No. of data = 2 x (quantity)
CRC-16
Higher 63 H
Lower 39 H