Modbus Module User Guide
9
Issue 1
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5.3
Examples
Command: Start
Message
Starter Address
Function Code
Register Address
Data
CRC
In
20
06
40002
1
CRC1, CRC2
Out
20
06
40002
1
CRC1, CRC2
Starter status: Running
Message
Starter Address
Function Code
Register Address
Data
CRC
In
20
03
40003
1
CRC1, CRC2
Out
20
03
2
xxxx0011
CRC1, CRC2
Trip code: Motor overload
Message
Starter Address
Function Code
Register Address
Data
CRC
In
20
03
40004
1
CRC1, CRC2
Out
20
03
2
00000010
CRC1, CRC2
Download parameter from starter
Digistart IS: Read parameter 3 (Pr
1C
)
Locked Rotor Time
, 10 seconds
Message
Starter Address
Function Code
Register Address
Data
CRC
In
20
03
40011
1
CRC1, CRC2
Out
20
03
2
10
CRC1, CRC2
Upload parameter to starter
Digistart IS Write parameter 12 (Pr
2H
),
Stop Mode
, set = 4 'STV Soft Stop'
Message
Starter Address
Function Code
Register Address
Data
CRC
In
20
06
40020
4
CRC1, CRC2
Out
20
06
40019
4
CRC1, CRC2
5.4
Modbus error codes
Table 5-3 Error codes
Code
Description
Example
01
Illegal function code
Function other than 03 or 06
02
Illegal data address
Register number invalid
03
Not readable data
Register not allowed for data reading
04
Not writable data
Register not allowed for data writing
05
Data boundary fault
Multiple data transfer across data boundary or data size more than 125
06
Invalid command code
e.g. writing "6" into 40003
07
Illegal parameter read
Invalid parameter number
08
Illegal parameter write
Invalid parameter number, read only, or hidden parameter
09
Unsupported command
Sending a serial command to Digistart IS with
Pr
3O = Disable control in RMT.
10
Local communication error
Communication error between Modbus slave and starter
NOTE
Some of the above codes are different from those defined in the Modbus Application Protocol Specification available
on www.modbus.org
.
