Danfoss FC 300 Design Manual page 262

11 RS-485 Installation and Set-up
Register Number
00001-00006
00007
00008
00009
00010-00990
01000-01990
02000-02990
03000-03990
04000-04990
...
49000-49990
50000
50010
...
50200
50210
* Used to specify the index number to be used when accessing an indexed parameter.
11.8.9 How to Control the Adjustable Frequency Drive
This section describes codes that can be used in the function and data fields of a Modbus RTU message. For a complete description of all the message
fields, please refer to the section
11.8.10 Function Codes Supported by Modbus RTU
Modbus RTU supports use of the following function codes in the function
field of a message:
11
Function
Diagnostics
11-16
Description
Reserved
Last error code from an adjustable frequency drive data object interface
Reserved
Parameter index*
000 parameter group (parameters 001 through 099)
100 parameter group (parameters 100 through 199)
200 parameter group (parameters 200 through 299)
300 parameter group (parameters 300 through 399)
400 parameter group (parameters 400 through 499)
...
4900 parameter group (parameters 4900 through 4999)
Input data: Adjustable frequency drive control word register (CTW).
Input data: Bus reference register (REF).
...
Output data: Adjustable frequency drive status word register (STW).
Output data: Adjustable frequency drive main actual value register (MAV).
Modbus RTU Message Framing Structure.
Function Code Sub-function code
8 1
2
10
11
12
13
14
MG.33.BC.22 - VLT
Holding registers
Function
Read coils
Read holding registers
Write single coil
Write single register
Write multiple coils
Write multiple registers
Get comm. event counter
Report slave ID
Sub-function
Restart communication
Return diagnostic register
Clear counters and diagnostic register
Return bus message count
Return bus communication error count
Return bus exception error count
Return slave message count
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FC 300 Design Guide
Function Code
1 hex
3 hex
5 hex
6 hex
F hex
10 hex
B hex
11 hex