Danfoss VLT Series Design Manual page 151

VLT ® HVAC Drive Design Guide
Register Number Description
00001-00006
00007
00008
00009
00100-00999
01000-01999
02000-02999
03000-03999
04000-04999
...
49000-49999
500000
50010
...
50200
50210
* Used to specify the index number to be used
when accessing an indexed parameter.
7.8.9. How to Control VLT HVAC
This section describes codes which 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
RTU Message Framing Structure.
7.8.10. Function Codes Supported by Modbus RTU
Modbus RTU supports use of the following
function codes in the function field of a mes-
sage:
Holding registers
Reserved
Last error code from an FC 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).
MG.11.B4.22 - VLT ® is a registered Danfoss trademark.
7. RS-485 Installation and Set-up
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 coun- B hex
ter
Report slave ID 11 hex
7
Modbus
151