How To Control The Frequency Converter; Function Codes Supported By Modbus Rtu - Danfoss VLT FC51 Design Manual

RS-485 Installation and Set...
Bus Bus PLC
adress Register
register 1)
0 1 40001
1 2 40002
2 3 40003
3 4 40004
4 5 40005
5 6 40006
6 7 40007
7 8 40008
8 9 40009
9 10 40010
19 20 40020
29 30 40030
Table 8.17 Adress/Registers
1)
Value written in Modbus RTU telegram must be one or less than register number. E.g. Read Modbus Register 1 by writing value 0 in telegram.
8.8.9 How to Control the Frequency
Converter
This section describes codes which can be used in the
function and data fields of a Modbus RTU message.
8.8.10 Function Codes Supported by
Modbus RTU
Modbus RTU supports use of the following function codes
in the function field of a message.
Function
Read coils
Read holding registers
Write single coil
Write single register
Write multiple coils
Write multiple registers
Get comm. event counter
Report follower ID
Table 8.18 Function Codes
®
VLT Micro Drive FC 51 Design Guide
Content Access
Reserved
Reserved
Reserved
Free
Free
Modbus conf Read/Write
Last error code Read only
Last error Read only
register
Index pointer Read/Write
FC par. 0-01 Dependent on
parameter access
FC par. 0-02 Dependent on
parameter access
FC par. xx-xx Dependent on
parameter access
Function code (hex)
1
3
5
6
F
10
B
11
MG02K302 - Rev. 2013-12-03
Description
Reserved for Legacy Drives VLT 5000 and VLT 2800
Reserved for Legacy Drives VLT 5000 and VLT 2800
Reserved for Legacy Drives VLT 5000 and VLT 2800
TCP only. Reserved for Modbus TCP (p12-28 and 12-29 -
store in Eeprom etc.)
Error code recieved from parameter database, refer to WHAT
38295 for details
Address of register with which last error occurred, refer to
WHAT 38296 for details
Sub index of parameter to be accessed. Refer to WHAT
38297 for details
Parameter 0-01 (Modbus Register=10 parameter number
20 bytes space reserved pr parameter in Modbus Map
Parameter 0-02
20 bytes space reserved pr parameter in Modbus Map
Parameter 0-03
20 bytes space reserved pr parameter in Modbus Map
Function Function Sub-
Code function
code
Diagnostics 8 1
2
10
11
12
13
14
Table 8.19 Function Codes
Sub-function
Restart communication
Return diagnostic register
Clear counters and
diagnostic register
Return bus message count
Return bus communi-
cation error count
Return follower error
count
Return follower message
count
75
8 8