Danfoss VLT FCD 322 Design Guide

VLT
®
FCD Series
■ Serial communication reference
The serial communication reference is transferred to
the frequency converter 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 follow-
ing format: 0-16384 (4000 Hex)

=
0-100% (Par. 204
Minimum ref. - Par. 205 Maximum 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 exam-
ple.
E
xample - Control word and serial communication
r
ef.:
The frequency converter is to receive a start com-
mand and the reference is to be set to 50% (2000
Hex) of the reference range.
Control word = 047F Hex ⇒ Start command.
Reference = 2000 Hex ⇒ 50% reference.
The frequency converter is to receive a start com-
mand and the reference is to be set to -50% (-2000
Hex) of the reference range.
The reference value is first converted to 1’ comple-
ment, and then 1 is added binarily to obtain 2’
complement:
2000 Hex 0010 0000 0000 0000 0000
1’ complement 1101 1111 1111 1111 1111
+1
2’ complement 1110 0000 0000 0000 0000
Control word = 047F Hex ⇒ Start command.
Reference = E000 Hex ⇒ -50% reference.
■ Present output frequency
The value of the frequency converter’s present out-
put frequency is transferred as a 16-bit word. The
value is transferred as whole numbers 0 - ±32767
(±200%).
16384 (4000 Hex) corresponds to 100%.
Output frequency has the following format:
0-16384 (4000 Hex)

=
0-100% (Par. 201 Output fre-
quency low limit - Par. 202 Output frequency high
limit).
E
xample - Status word and current output frequency:
The master receives a status message from the fre-
quency converter that the current output frequency is
50% of the output frequency range.
Par. 201 Output frequency low limit =0Hz
Par. 202 Output frequency high limit =50Hz
Status word = 0F03 Hex.
Output frequency= 2000 Hex ⇒ 50% of the fre-
quency range, corresponding to 25 Hz.
MG.04.A1.02 - VLT is a registered Danfoss trade mark
105
Programming

Danfoss VLT FCD 322 Specifications

General

Brand	Danfoss
Model	VLT FCD 322
Category	DC Drives
Language	English