Danfoss VLT Midi Drive FC 280 Programming Manual page 55

Parameter Descriptions
Preset ref. bit
Preset ref. 0
Preset ref. 1
Preset ref. 2
Preset ref. 3
Preset ref. 4
Preset ref. 5
Preset ref. 6
Preset ref. 7
Table 4.1 Preset Ref. Bit
[19] Freeze Freeze the actual reference, which is now the point
ref of enable/condition for [21] Speed up and [22]
Speed down to be used. If [21] Speed up or [22]
Speed down is used, the speed change always
follows ramp 2 (parameter 3-51 Ramp 2 Ramp Up
Time and parameter 3-52 Ramp 2 Ramp Down Time)
in the range 0–parameter 3-03 Maximum Reference.
NOTICE
[20] Freeze
output
When [20] Freeze output is active, the
frequency converter cannot be stopped by
setting the signal on [8] Start to low. Stop
the frequency converter via a terminal
programmed for [2] Coasting inverse or [3]
Coast and reset, inverse.
Freeze the actual motor frequency (Hz), which is
now the point of enable/condition for [21] Speed
up and [22] Speed down to be used. If [21] Speed up
or [22] Speed down is used, the speed change
always follows ramp 2 (parameter 3-51 Ramp 2
Ramp Up Time and parameter 3-52 Ramp 2 Ramp
Down Time) in the range 0–parameter 1-23 Motor
Frequency.
[21] Speed Select [21] Speed up and [22] Speed down if digital
up control of the up/down speed is needed (motor
potentiometer). Activate this function by selecting
either [19] Freeze reference or [20] Freeze output.
When speed up/down is activated for less than 400
ms, the resulting reference is increased/decreased
by 0.1%. If speed up/down is activated for more
than 400 ms, the resulting reference follows the
setting in ramping up/down parameter 3-x1/3-x2.
Unchanged speed
Reduced by %-value
Increased by %-value
Reduced by %-value
Table 4.2 Shut Down/Catch Up
[22] Speed Same as [21] Speed up.
down
[23] Set-up Select [23] Set-up select bit 0 or [1] Set-up select
select bit bit 1 to select 1 of the 2 set-ups. Set
0 parameter 0-10 Active Set-up to [9] Multi Set-up.
MG07C302
Programming Guide
2 1 0
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
Shut down Catch up
0 0
1 0
0 1
1 1
Danfoss A/S © 07/2016 All rights reserved.
[24] Set-up Default digital input 32. Same as [23] Set-up select
select bit bit 0.
1
[26] Precise Precise stop inverse function is available for
stop inv. terminals 18 or 19.
[27] Precise
start
stop
[28] Catch up Increase reference value by percentage (relative)
set in parameter 3-12 Catch up/slow Down Value.
[29] Slow Reduce reference value by percentage (relative)
down set in parameter 3-12 Catch up/slow Down Value.
[32] Pulse Measure the duration between pulse flanks. This
time- parameter has a higher resolution at lower
based frequencies, but is not as precise at higher
frequencies. This principle has a cut-off
frequency, which makes it unsuited for encoders
with low resolutions (for example 30 PPR) at low
speeds.
Speed [rpm]
a Time[sec]
a: Low encoder
resolution
Pulse
Timer
Sample time
Time counter
Time Start
Illustration 4.9 Duration Between Pulse Flanks
[34] Ramp bit Enable a selection from the 4 ramps available,
0 according to Table 4.3.
[35] Ramp bit Same as ramp bit 0.
1
Preset ramp bit
Ramp 1
Ramp 2
Ramp 3
Ramp 4
Table 4.3 Preset Ramp Bits
[40] Latched A latched precise start only requires a pulse
precise of 3 ms on terminals 18 or 19 when using
start parameter 1-83 Precise Stop Function [1]
Counter stop with resetor [2] Counter stop
without reset. When the reference is reached,
the frequency converter internally enables the
precise stop signal. This means that the
frequency converter does the precise stop
when the counter value of
parameter 1-84 Precise Stop Counter Value is
reached.
Speed [rpm]
b Time[sec]
b: Standard encoder
resolution
Read Timer: Read Timer:
20 timer tides 20 timer tides
1 0
0 0
0 1
1 0
1 1
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4 4