Danfoss VLT FCD 311 Design Manual page 76

NB!:
If Freeze output is active the frequency con-
verter can only be stopped if you select Motor
coast, Quick stop or DC braking via a digital input.
Speed up and Speed down are selected if digital
control of the up/down speed is required. This func-
tion is only active if Freeze reference or Freeze
output frequency has been selected.
If Speed up is active the reference or output fre-
quency will be increased, and if Speed down is
active the reference or output frequency will be re-
duced. The output frequency is changed via the
preset ramp times in parameters 209-210 Ramp 2.
One pulse (logic '1' minimum high for 14 ms and a
minimum break time of 14 ms) will lead to a speed
change of 0.1 % (reference) or 0.1 Hz (output fre-
quency). Example:
Term. Term. Freeze ref/
29 33 freeze outp.
0 0 1
0 1 1
1 0 1
1 1 1
Freeze reference can be changed even if the fre-
quency converter has stopped. The reference will
also be saved if the mains are disconnected
Catch-up/Slow-down is selected if the reference
value is to be increased or reduced by a pro-
grammable percentage value set in parameter 219
Catch-up/Slow-down reference.
Slow-down Catch-up
0 0
0 1
1 0
1 1
Ramp 2 is selected if a shift between ramp 1
(parameters 207-208) and ramp 2 (parameters 209-
210) is required. Logic '0' leads to ramp 1 and logic
'1' leads to ramp 2.
Preset reference, lsb and Preset reference, msb
makes it possible to select one of the four preset ref-
erences, see the table below:
= factory setting. () = display text [] = value for use in communication via serial communication port
76
Function
No speed change
Speed up
Speed down
Speed down
Function
Unchanged speed
Increase by % value
Reduce by % value
Reduce by % value
®
VLT FCD Series
Preset ref. Preset ref.
msb lsb
0 0
0 1
1 0
1 1
Preset reference on is used for shifting between
remote-controlled reference and preset reference. It
is assumed that External/preset [2] has been se-
lected in parameter 214 Reference function. Logic
'0' = remote-controlled references are active, logic '1'
= one of the four preset references is active, as can
be seen from the table above.
Precise stop, inverse is selected to obtain a high de-
gree of accuracy when a stop command is repeated.
A logic 0 means that the motor speed is ramped
down to stop via the selected ramp.
Precise start/stop is selected to obtain a high degree
of accuracy when a start and stop command is re-
peated.
Pulse reference is selected if the reference signal
applied is a pulse train (frequency). 0 Hz corre-
sponds to parameter 204 Minimum reference,
Ref . The frequency set in parameter 327/328
MIN
Pulse Max 33/29 corresponds to parameter 205
Maximum reference Ref
MAX
Pulse feedback is selected if the feedback signal
used is a pulse train (frequency). In parameter 327/
328 Pulse Max 33/29 the maximum pulse feedback
frequency is set.
Pulse input is selected if a specific number of pulses
must lead to a Precise stop, see parameter 343 Pre-
cise stop and parameter 344 Counter value.
Selection of Setup, lsb and Selection of Setup, msb
gives the possibility to select one of the four setups.
It is, however, a condition that parameter 004 is set
to Multisetup.
Reset and start can be used as a start function. If
24 V are connected to the digital input, this will
cause the frequency converter to reset and the mo-
tor will ramp up to the preset reference.
Encoder reference is selected if the reference signal
applied is a pulse train (frequency). 0 Hz corre-
sponds to parameter 204 Minimum reference,
Ref . The frequency set in parameter 327/328
MIN
MG.04.A1.02 - VLT is a registered Danfoss trade mark
Function
Preset ref. 1
Preset ref. 2
Preset ref. 3
Preset ref. 4
.