Danfoss VLT AQUA Drive FC 202 Programming Manual page 142

Parameter Description
20-73 Minimum Feedback Level
Range:
-999999
ProcessCtrlUnit
3 3
20-74 Maximum Feedback Level
Range:
999999
ProcessCtrlUnit
20-79 PID Autotuning
Option:
[0] Disabled
[1] Enabled
3.17.4 20-8* PID Basic Settings
This parameter group is used to configure the basic
operation of the frequency converter's PID Controller,
including how it responds to a feedback that is above or
below the setpoint, the speed at which it first starts
functioning, and when it indicates that the system has
reached the setpoint.
20-81 PID Normal/ Inverse Control
Option: Function:
[0] Normal The frequency converter's output frequency
decreases when the feedback is greater than the
setpoint reference. This is common for pressure-
controlled supply fan and pump applications.
[1] Inverse The frequency converter's output frequency
increases when the feedback is greater than the
setpoint reference.
140
Function:
[ -999999.999 - The minimum allowable
par. 20-74 feedback level should be
*
ProcessCtrlUnit] entered here in user units as
defined in 20-12 Reference/
Feedback Unit. If the level falls
below
parameter 20-73 Minimum
Feedback Level, autotuning is
aborted and an error
message appears in the LCP.
Function:
[ par. 20-73 - The maximum allowable
999999.999 feedback level should be
*
ProcessCtrlUnit] entered here in user units as
defined in 20-12 Reference/
Feedback Unit. If the level
rises above
parameter 20-74 Maximum
Feedback Level, autotuning is
aborted and an error
message appears in the LCP.
Function:
This parameter starts the PID autotuning sequence.
Once the autotuning has successfully completed
and the settings have been accepted or rejected
by the user, by pressing [OK] or [Cancel] at the end
of tuning, this parameter is reset to [0] Disabled.
Danfoss A/S © Rev. 2014-01-21 All rights reserved.
Programming Guide
20-82 PID Start Speed [RPM]
Range:
Size
related
*
20-83 PID Start Speed [Hz]
Range:
Size
related
*
20-84 On Reference Bandwidth
Range:
5 %
*
200 %]
Function:
[ 0 - When the frequency converter is first
par. 4-13 started, it initially ramps up to this output
RPM] speed in open loop mode, following the
active ramp up time. When the output
speed programmed is reached, the
frequency converter automatically switches
to closed loop mode and the PID
Controller begins to function. This is useful
in applications that require quick
acceleration to a minimum speed at start-
up.
NOTICE
This parameter is only visible if
parameter 0-02 Motor Speed Unit is
set to [0] RPM.
Function:
[ 0 - When the frequency converter is first
par. started, it initially ramps up to this output
4-14 Hz] frequency in open loop mode, following
the active ramp up time. When the output
frequency programmed here is reached, the
frequency converter will automatically
switch to closed loop mode and the PID
Controller begins to function. This is useful
in applications that require quick
acceleration to a minimum speed at start-
up.
NOTICE
This parameter is only visible if
parameter 0-02 Motor Speed Unit is
set to [1] Hz.
Function:
[0 - When the difference between the feedback and
the setpoint reference is less than the value of
this parameter, the frequency converter's display
shows "Run on Reference". This status can be
communicated externally by programming the
function of a digital output for [8] Run on
Reference/No Warning. In addition, for serial
communications, the On Reference status bit of
the frequency converter's status word is high (1).
The On Reference Bandwidth is calculated as a
percentage of the setpoint reference.
MG20O702