YASKAWA HV600 Technical Reference page 744

10.6 MEMOBUS/Modbus Communications
Description
XOR w A001 (Hex.)
XOR result
Shift 7
Shift 8
XOR w A001 (Hex.)
XOR result
Perform operations with next data (function code)
Response Data
The drive does the CRC-16 calculation for the response message and makes sure that the data does not have errors.
Make sure that the calculated value is the same value as the CRC-16 in the response message.
◆
Examples of Messages for Commands/Responses
The items in this section are examples of messages for commands/responses.
■
Read Multiple Holding Registers
Uses function code 03 (Hex.) to read the contents of a maximum of 16 holding registers.
Table 10.23 shows example messages when the drive reads status signal from the drive of slave 2, the error contents,
fault contents, and frequency references.
Table 10.23 Message Example When Reading the Contents of Holding Register
Byte Command Message
0 Slave address
1 Function code
2
Starting No.
3
4
Data Qty
5
6
CRC-16
7
8
9
10
11
12
■
Loopback Test
The loopback test uses function code 08 (Hex.) and returns the command message as a response message. This test
checks communication between the master and slave. The test code and data can use desired values.
Table 10.24 shows examples of messages given out when the loopback test is done with the drive of slave 1.
744
Calculation Overflow
1010 0000 0000 0001
1000 0100 1111 1110
0100 0010 0111 1111
0010 0001 0011 1111
1010 0000 0000 0001
1000 0001 0011 1110
Setting Data
Response Message (Normal)
(Hex.)
02
03
Upper 00
Lower 20
First storage
register
Upper 00
Lower 04
Next storage
register
Upper 45
Lower F0
Next storage
register
-
-
Next storage
register
-
-
CRC-16
-
Description
- XOR result
- Shift 7
0 XOR w A001 (Hex.)
1 XOR result
- Shift 8
- XOR w A001 (Hex.)
XOR result
CRC-16
Setting Data
(Hex.)
Slave address 02
Function code 03
Data Qty 08
Upper 00
Lower 65
Upper 00
Lower 00
Upper 00
Lower 00
Upper 01
Lower F4
Upper AF
Lower 82
YASKAWA SIEPYAIH6B01A HV600 AC Drive Bypass Technical Reference
Calculation
1000 0101 0000 0101
0100 0010 1000 0010
1010 0000 0000 0001
1110 0010 1000 0011
0111 0001 0100 0001
1010 0000 0000 0001
1101 0001 0100 0000
1101 0001 0100 0000
D 1 4 0
(Lower) (Upper)
Continue from here with next data.
Response Message (Fault)
Slave address
Function code
Error code
Upper
CRC-16
Lower
-
-
-
-
-
-
-
-
Overflow
-
1
-
-
1
-
-
-
-
Setting Data
(Hex.)
02
83
03
F1
31