Danfoss VLT HVAC Basic Drive FC 101 Design Manual page 95

RS-485 Installation and Set...
7.11.3 Bus Speed Reference Value
Speed reference value is transmitted to the frequency
converter in a relative value in %. The value is transmitted
in the form of a 16-bit word; in integers (0-32767) the
value 16384 (4000 Hex) corresponds to 100%. Negative
figures are formatted by means of 2's complement. The
Actual Output frequency (MAV) is scaled in the same way
as the bus reference.
The reference and MAV are scaled as follows:
Par.3-00 set to
(1) -max- +max
7 7
Par.3-00 set to
(0) min-max
Illustration 7.16
94
®
VLT HVAC Basic Drive Design Guide
-100%
(C000hex)
Reverse
Par.3-03
Max reference
®
MG18C402 - VLT is a registered Danfoss trademark
Master-slave
CTW Speed ref.
Slave-master
Actual output
STW
freq.
Illustration 7.15
0%
(0hex)
Forward
0
0%
(0hex)
Forward
Par.3-02
Min reference
16bit
100%
(4000hex)
Par.3-03
Max reference
100%
(4000hex)
Par.3-03
Max reference