Siemens SED2 Commissioning Manual page 91

Note: Allows the user to scale the PID feedback as a percentage value [%]
A gain of 100.0% means that feedback signal has not changed from its default value.
P2270 PID feedback function selector
Applies mathematical functions to the PID feedback signal, allowing multiplication of the result
by P2269 (gain applied to PID feedback).
Unit: - Min: 0
Settings: 0=Disabled
P2271 PID transducer type
Allows the user to select the transducer type for the PID feedback signal
Unit: - Min: 0
Value: 0: [default] If the feedback signal is less than the PID setpoint, the PID controller will increase motor speed to correct this
1: If the feedback signal is greater than the PID setpoint, the PID controller will reduce motor speed to correct this
Settings: 0=Disabled
Note: It is essential that you select the correct transducer type.
If you are unsure whether 0 or 1 is applicable, you can determine the correct type as follows:
1. Disable the PID function (P2200=0)
2. Increase the motor frequency while measuring the feedback signal
3. If the feedback signal increases with an increase in motor frequency, the PID transducer type should be 0
4. If the feedback signal decreases with an increase in motor frequency, the PID transducer type should be set to 1
r2272 CO: PID scaled feedback
Displays PID scaled feedback signal in [%].
Unit: % Min: -
Note: r2272=100% corresponds to 4000 hex
r2273 CO: PID error
Displays PID error (difference) signal between setpoint and feedback signals in [%].
Unit: % Min: -
Note: r2273=100% corresponds to 4000 hex
P2274 PID derivative time
Sets PID derivative action time.
Unit: s Min: 0
P2279 PID Neutral zone
Sets PID Neutral zone.
Unit: % Min: 0.00
P2280 PID proportional gain
Allows user to set proportional gain for PID controller.
The PID controller is implemented using the standard model.
Unit: - Min: 0.000
Details: For best results, enable both P and I parts
Dependency: If P part=0, I part acts on the square of the error signal
Note: If the system is prone to sudden step changes in the feedback signal, P part should normally be set to a small value
(0.5) with a faster I part for optimum performance.
The D part (P2274) multiplies the difference between the present and the previous feedback signal, thus accelerating the
controller response to an error that appears suddenly.
The D part should be used carefully, since it can cause the controller output to fluctuate as every change in the feedback
signal is amplified by the controller derivative action.
P2285 PID integral time
Sets integral action time constant for PID controller.
Unit: s Min: 0.000
Note: See P2280 (PID proportional gain)
P2291 PID output upper limit
Sets the upper limit for PID controller output in [%].
Unit: % Min: 0.00
Dependency: If F max (P1082) is greater than P2000 (reference frequency), either P2000 or P2291 (PID output upper limit) must be
changed to achieve F max.
Note: P2291=100% corresponds to 4000 hex (as defined by P2000 [reference frequency]).
When staging P2291 must not be set below 100%.
P2292 PID output lower limit
Sets the lower limit for the PID controller output in [%].
Unit: % Min: -0.00
Dependency: A negative value allows bipolar operation of the PID controller.
Note: P2292=100% corresponds to 4000 hex
P2293 Ramp-up /-down time of PID limit
Sets maximum ramp rate on output of PID.
When PI is enabled, the output limits are ramped up from 0 to the limits set in P2291 (PID
output upper limit) and P2292 (PID output lower limit). Limits prevent large step changes
appearing on the output of the PID when the VSD is started. Once the limits have been
reached, the PID controller output is instantaneous.
These ramp times are used whenever a RUN command is given.
Unit: s Min: 0.00
Siemens
Building Technologies
Def: 0
1=Square root (root(x))
Def: 0
Def: -
Def: -
Def: 0
Def: 0.00
Def: 1.200
Def: 30
Def: 100.00
Def: 0.00
Def: 0.00
Commissioning Guide
10 Parameterization
Max: 3
2=Square (x*x)
Max: 1
1=Inversion of PID feedback signal
Max: -
Max: -
Max: 65535
Max: 100.00
Max: 65.000
Max: 65535
Max: 100.00
Max: 100.00
Max: 100.00
Level 3
3=Cube (x*x*x)
Level 3
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CM1G5192en
29.07.2010