YASKAWA H6B1A002, Technical Reference

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10.6 MEMOBUS/Modbus Communications
742 YASKAWA SIEPYAIH6B01A HV600 AC Drive Bypass Technical Reference
Figure 10.22 Response Wait Time
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Message Format
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Communication Message Description
In MEMOBUS/Modbus communications, the master sends commands to the slave, then the slave responds. The
master and slave send their messages in the configuration in
Figure 10.23 . The length of the data changes when the
description of the command (function) changes.
Figure 10.23 Message Format
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Slave Address
Set the slave address of the drive to 01 to FF (Hex.).
Broadcast Messages
When the master broadcasts to a slave address of 00 (Hex), all slaves will receive the message. Slaves will provide no
response to a broadcast message.
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Function Code
There are five function codes that set commands. Table 10.21 shows the different codes.
Table 10.21 Function Codes
Function Code
(Hex.)
Subfunction Code
(Hex.)
Function
Command Message Response Message
Minimum Data
Length
(byte)
Maximum Data
Length
(byte)
Minimum Data
Length
(byte)
Maximum Data
Length
(byte)
03 -
Read Multiple Holding
Registers
8 8 7 37
08 - Loopback Test 8 8 8 8
10 -
Writing to Multiple
Holding Registers
11 41 8 8
5A -
Writing to Multiple
Holding Registers /
Reading the Register
Indicated
11 41 17 17
67
010D
Reading the Contents of
Non-Consecutive
Holding Registers
10 248 10 248
010E
Writing to Non-
Consecutive Holding
Registers
14 250 8 8