How To Control The Frequency Converter; Function Codes Supported By Modbus Rtu - Danfoss VLT Compressor Drive CDS 803 Design Manual

RS485 Installation and Set-...
Bus Bus
address
register
0 1
1 2
2 3
3 4
4 5
5 6
6 7
7 8
7 7
8 9
9 10
19 20
29 30
Table 7.18 Address/Registers
1) Value written in the Modbus RTU telegram must be 1 or less than the register number. For example, Read Modbus Register 1 by writing value 0
in the telegram.
7.8.9 How to Control the Frequency
Converter
This section describes codes which can be used in the
function and data fields of a Modbus RTU telegram.
60
VLT
PLC Content
1) register
40001 Reserved
40002 Reserved
40003 Reserved
40004 Free
40005 Free
40006 Modbus configuration
40007 Last fault code
40008 Last error register
40009 Index pointer
40010 Parameter 0-01 Language
40020 Parameter 0-02 Motor Speed
Unit
40030 Parameter 0-03 Regional
Settings
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®
Compressor Drive CDS 803
Access Description
Reserved for legacy frequency converters VLT
–
VLT
Reserved for legacy frequency converters VLT
–
VLT
Reserved for legacy frequency converters VLT
–
VLT
–
–
Read/Write TCP only. Reserved for Modbus TCP
(parameter 12-28 Store Data Values and
parameter 12-29 Store Always - stored in, for example,
EEPROM).
Read only Fault code received from parameter database, refer to
WHAT 38295 for details.
Read only Address of register with which last error occurred, refer
to WHAT 38296 for details.
Read/Write Sub index of parameter to be accessed. Refer to WHAT
38297 for details.
Dependent on Parameter 0-01 Language (Modbus register = 10
parameter parameter number)
access 20 bytes space reserved for parameter in Modbus map.
Dependent on Parameter 0-02 Motor Speed Unit
parameter 20 bytes space reserved for parameter in Modbus map.
access
Dependent on Parameter 0-03 Regional Settings
parameter 20 bytes space reserved for parameter in Modbus map.
access
7.8.10 Function Codes Supported by
Modbus RTU
Modbus RTU supports use of the following function codes
in the function field of a telegram.
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
Table 7.19 Function Codes
®
2800.
®
2800.
®
2800.
–
–
Function code (hex)
1
3
5
6
F
10
B
11
®
5000 and
®
5000 and
®
5000 and
MG18N202