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Option
Function
[26] Precise
stop inv.
Sends an inverted stop signal when the precise stop function is activated in
parameter 1-83 Precise Stop Func-
tion
. Precise stop inverse function is available for terminals 18 or 19.
[27] Precise
start, stop
Use when
[0] Precise ramp stop
is selected in
parameter 1-83 Precise Stop Function
. Precise start, stop is availa-
ble for terminals 18 and 19. Precise start ensures that the rotor turning angle from standing still to reference
is the same for each start (for same ramp time, same setpoint). This function is the equivalent to the precise
stop where the rotor turning angle from reference to standstill is the same for each stop. When using
param-
eter 1-83 Precise Stop Function
option
[1] Cnt stop with reset
or
[2] Cnt stop w/o reset
: The drive needs a precise
stop signal before reaching the value of
parameter 1-84 Precise Stop Counter Value
. If this signal is not sup-
plied, the drive does not stop when the value in
parameter 1-84 Precise Stop Counter Value
is reached. Trigger
precise start, stop by a digital input. The function is available for terminals 18 and 19.
[28] Catch up
Increases reference value by percentage (relative) set in
parameter 3-12 Catch up/slow Down Value
.
[29] Slow down
Reduces reference value by percentage (relative) set in
parameter 3-12 Catch up/slow Down Value
.
[30] Counter in-
put
Precise stop function in
parameter 1-83 Precise Stop Function
acts as counter stop or speed-compensated
counter stop with or without reset. Set the counter value in
parameter 1-84 Precise Stop Counter Value
.
[31] Pulse edge
triggered
Counts the number of pulse flanks per sample time. This gives a higher resolution at high frequencies, but is
not as precise at lower frequencies. Use this pulse principle for encoders with low resolution (for example
30 PPR).
Pulse
Sample time
e3
0b
b4
63
.1
0
Illustration 61: Pulse Flanks per Sample Time
[32] Pulse time-
based
Measures the duration between pulse flanks. This gives a higher resolution at lower frequencies, but is not
as precise at higher frequencies. This principle has a cutoff frequency, which makes it unsuited for encoders
with low resolutions (for example 30 PPR) at low speeds.
Spee d [rpm]
Spee d [rpm]
Time[sec]
Time[sec]
a
b
e3
0b
b4
62
.1
0
Read Timer:
20 timer tides
Read Timer:
20 timer tides
Time Start
Time counter
Sample time
Timer
Pulse
e3
0b
b4
64
.1
0
Illustration 62: Duration Between Pulse Flanks
[34] Ramp bit 0
Enables a selection between 1 of the 4 ramps available, according to
.
[35] Ramp bit 1
Same as
[34] Ramp bit 0
.
Table 333: Preset Ramp Bit
Preset ramp bit
1
0
Ramp 1
0
0
Ramp 2
0
1
Ramp 3
1
0
Ramp 4
1
1
AU275636650261en-000101 / 130R0334
182 | Danfoss A/S © 2022.12
Parameter Descriptions
VLT AutomationDrive FC 301/302
Programming Guide