![background image](http://html.mh-extra.com/html/danfoss/fc-300/fc-300_design-manual_507599262.webp)
Holding registers
Register Number
Description
00001-00006
Reserved
00007
Last error code from an adjustable frequency drive data object interface
00008
Reserved
00009
Parameter index*
00010-00990
000 parameter group (parameters 001 through 099)
01000-01990
100 parameter group (parameters 100 through 199)
02000-02990
200 parameter group (parameters 200 through 299)
03000-03990
300 parameter group (parameters 300 through 399)
04000-04990
400 parameter group (parameters 400 through 499)
...
...
49000-49990
4900 parameter group (parameters 4900 through 4999)
50000
Input data: Adjustable frequency drive control word register (CTW).
50010
Input data: Bus reference register (REF).
...
...
50200
Output data: Adjustable frequency drive status word register (STW).
50210
Output data: Adjustable frequency drive main actual value register (MAV).
* 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
Modbus RTU Message Framing Structure.
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:
Function
Function Code
Read coils
1 hex
Read holding registers
3 hex
Write single coil
5 hex
Write single register
6 hex
Write multiple coils
F hex
Write multiple registers
10 hex
Get comm. event counter
B hex
Report slave ID
11 hex
Function
Function Code
Sub-function code
Sub-function
Diagnostics
8
1
Restart communication
2
Return diagnostic register
10
Clear counters and diagnostic register
11
Return bus message count
12
Return bus communication error count
13
Return bus exception error count
14
Return slave message count
11 RS-485 Installation and Set-up
FC 300 Design Guide
11-16
MG.33.BC.22 - VLT
®
is a registered Danfoss trademark
11