
8.5.12
Short setup of Modbus
In the following, the steps required for controlling the inverter via Modbus are described.
Parameterisation required
1
.
Activate network:
0x2631:037 (PAR 400/037)
= "1: TRUE"
2
.
Set network as default setpoint source:
0x2860:001 (PAR 201/001)
= "5: Network"
3
.
Set Modbus node address.
4
Modbus node address
^
127
4
.
Set Modbus baud rate.
4
Modbus baud rate
^
128
•
Default setting: automatic detection.
•
If the automatic baud rate detection function is activated, the first 5 ... 10 messages are
lost after switch-on.
5
.
Set Modbus data format.
4
Modbus data format
^
128
•
Default setting: automatic detection.
•
If the automatic data format detection function is activated, the first 5 ... 10 messages are
lost after switch-on.
Digital input DI1 is assigned with the "Start enable" function by default and
therefore must be set to HIGH level.
4
Controller enable, starting & stopping,
reversal
^
188
Starting/stopping the drive via Modbus
For starting/stopping the drive, Modbus register 42101 can be used.
•
Modbus register 42101 is permanently assigned to the AC Drive control word
0x400B:001
(PAR 592/001)
.
•
In the frame, the leading 4 is omitted in the addressing process. The numbering of the regis-
ters starts with 1; addressing, however starts with 0. Therefore the address 2100 (0x0834) is
used in the frame when register 42101 is written.
Bits set in the AC Drive control word:
•
Bit 0 ≡ forward operation
•
Bit 5 ≡ network control
•
Bit 6 ≡ network setpoint set
Example of an inverter with the node address 1:
Request frame by the master
Slave address
Function code
Data
Checksum (CRC)
Register address
AC Drive control word
0x01
0x06
0x08
0x34
0x00
0x61
0x0B
0x8C
If digital input DI1 ("Start enable") is set to HIGH level, the drive should start and the inverter
should respond with the same frame as confirmation:
Response message from the inverter
Slave address
Function code
Data
Checksum (CRC)
Register address
AC Drive control word
0x01
0x06
0x08
0x34
0x00
0x61
0x0B
0x8C
Configuring the network
Modbus
Short setup of Modbus
137
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