Examples; Modbus Rtu Overview - Danfoss VLT AQUA Design Manual

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VLT AQUA Drive Design Guide

7.5. Examples

7.5.1. Writing a parameter value
Motor Speed High Limit [Hz]
Change par. 4-14
Write the data in EEPROM.
PKE = E19E Hex - Write single word in par. 4-14
[Hz]
IND = 0000 Hex
PWEHIGH = 0000 Hex
PWELOW = 03E8 Hex - Data value 1000, corresponding to 100 Hz, see
Conversion.
Note: Parameter 4-14 is a single word, and the parameter command for
write in EEPROM is "E". Parameter number 414 is 19E in hexadecimal.
The response from the slave to the master will be:
7.5.2. Reading a parameter value
Read the value in par. 3-41 Ramp 1 Up Time.
PKE = 1155 Hex - Read parameter value in par. 3-41
IND = 0000 Hex
PWEHIGH = 0000 Hex
PWELOW = 0000 Hex
If the value in par. 3-41 Ramp 1 Up Time
slave to the master will be:
NB!
3E8 Hex corresponds to 1000 decimal. The conversion index for par. 3-41 is -2, i.e. 0.01.

7.6. Modbus RTU Overview

7.6.1. Assumptions
These operating instructions assume that the installed controller supports the interfaces in this document and that all the requirements stipulated in the
controller, as well as the frequency converter, are strictly observed, along with all limitations therein.
to 100 Hz.
Motor Speed High Limit
Ramp 1 Up Time
is 10 s, the response from the
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MG.20.N3.02 - VLT is a registered Danfoss trademark
7. RS-485 Installation and Set-up
The telegram will look like this:
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