Danfoss VLT AutomationDrive FC 300 Programming Manual page 81

Parameter Descriptions
and Speed down to be used. If Speed up/down is
used, the speed change always follows ramp 2
(3-51 Ramp 2 Ramp Up Time and 3-52 Ramp 2
Ramp Down Time) in the range 0 - 1-23 Motor
Frequency.
NOTE
When Freeze output is active, the frequency
converter cannot be stopped via a low 'start
[8]' signal. Stop the frequency converter via a
terminal programmed for Coasting inverse [2]
or Coast and reset, inverse.
[21] Speed Select Speed up and Speed down if digital control
up of the up/down speed is desired (motor potenti-
ometer). Activate this function by selecting either
Freeze reference or Freeze output. When Speed
up/down is activated for less than 400 ms the
resulting reference will be increased/ decreased by
0.1 %. If Speed up/down is activated for more than
400 ms the resulting reference will follow the
setting in ramping up/down parameter 3-x1/ 3-x2.
Unchanged speed
Reduced by %-value
Increased by %-value
Reduced by %-value
Table 3.14 Shut Down/Catch Up
[22] Speed Same as [21] Speed up.
down
[23] Set-up Select Set-up select bit 0 or Select Set-up select
select bit bit 1 to select one of the four set-ups. Set
0 0-10 Active Set-up to Multi Set-up.
[24] Set-up (Default Digital input 32): Same as [23] Set-up
select bit select bit 0.
1
[26] Precise Sends an inverted stop signal when the precise
stop inv. stop function is activated in 1-83 Precise Stop
Function.
Precise stop inverse function is available for
terminals 18 or 19.
[27] Precise Use when Precise ramp stop [0] is selected in
start, stop 1-83 Precise Stop Function.
Precise start, stop is available for terminals 18
and 19.
Precise start makes sure that the angle that the
rotor turns from standing still to reference is the
same for each start (for same ramp time, same
set-point). This is the equivalent to the precise
stop where the angle that the rotor turns from
reference to standing still is the same for each
stop.
When using for 1-83 Precise Stop Function [1] or
[2]:
The frequency converter needs a Precise Stop
signal before the value of 1-84 Precise Stop
Counter Value is reached. If this is not supplied,
®
VLT AutomationDrive Programming Guide
Shut down Catch up
0 0
1 0
0 1
1 1
®
MG33MG02 - VLT is a registered Danfoss trademark
the frequency converter will not stop when the
value in 1-84 Precise Stop Counter Value is
reached.
Precise start, stop must be triggered by a Digital
Input and is available for terminals 18 and 19.
[28] Catch up Increases reference value by percentage
(relative) set in 3-12 Catch up/slow Down Value.
[29] Slow Reduces reference value by percentage (relative)
down set in 3-12 Catch up/slow Down Value.
[30] Counter Precise stop function in 1-83 Precise Stop
input Function acts as Counter stop or speed
compensated counter stop with or without
reset. The counter value must be set in
1-84 Precise Stop Counter Value.
[31] Pulse Counts the number of pulse flanks per sample
edge time. This gives a higher resolution at high
triggered frequencies, but is not as precise at lower
frequencies. Use this pulse principle for
encoders with very low resolution (e.g. 30 ppr).
Pulse
Sample time
Illustration 3.33 Pulse Flanks per Sample Time
[32] Pulse time Measures the duration between pulse flanks.
based This gives a higher resolution at lower
frequencies, but is not as precise at higher
frequencies. This principle has a cut-off
frequency which makes it unsuited for encoders
with very low resolutions (e.g. 30 ppr) at low
speeds.
Speed [rpm]
a Time[sec]
a: very low encoder
resolution
Table 3.15
Pulse
Timer
Sample time
Time counter
Time Start
Illustration 3.34 Duration Between Pulse Flanks
[34] Ramp bit Enables a choice between one of the 4 ramps
0 available, according to the table below.
[35] Ramp bit Same as Ramp bit 0.
1
Speed [rpm]
b Time[sec]
b: standard encoder
resolution
Read Timer: Read Timer:
20 timer tides 20 timer tides
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