Serial Communication Reference - Danfoss FC 300 Design Manual

FC 300 Design Guide

Serial Communication Reference

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The serial communication reference is transferred
to the adjustable frequency drive as a 16-bit
word. The value is transferred in whole
numbers 0 - ±32767 (±200%).
16384 (4000 Hex) corresponds to 100%.
The serial communication reference has the following format: 0-16384 (4000 Hex)
(par. 3-02 Minimum Ref. to par. 3-03Maximum Ref.).
It is possible to change the direction of rotation via the serial reference. This is done by converting
the binary reference value to 2' complement. See example.
Example - Control word and serial communication ref.:
The adjustable frequency drive receives a start
command and the reference is set to 50%
(2000 Hex) of the reference range.
Control word = 047F Hex => Start command.
Reference = 2000 Hex => 50% reference.
The adjustable frequency drive receives a start
command and the reference is set to -50%
(-2000 Hex) of the reference range.
The reference value is first converted to 1'
complement, and then 1 is added in binary
fashion to obtain 2' complement:
Control word = 047F Hex => Start command.
Reference = E000 Hex => -50% reference.
* default setting ( )
How to Program
display text [ ] value for use in communication via serial communication port
MG.33.B6.22 - VLT is a registered Danfoss trademark
2000 Hex 0010 0000 0000 0000 0000
1' complement 1101 1111 1111 1111 1111
2' complement 1110 0000 0000 0000 0000
0-100%
+ 1
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