Bronkhorst IQ+FLOW (till 01-07-2013) - Manual (Page 23)

9.17.045 page 23
Controller Speed (Kspeed)
Type Access Range FlowDDE FlowBus Modbus
Float RW  0…3.4E+38 254 114/30 0xF2F0…0xF2F1/62193…62194
This parameter is the controller speed factor. PID-Kp is multiplied by this factor.
Ti (PID-Ti)
Type Access Range FlowDDE FlowBus Modbus
Float RW  0…1E+10 168 114/22 0xF2B0…0xF2B1/62129…62130
PID controller integration action in seconds. This value should not be changed.
Td (PID-Td)
Type Access Range FlowDDE FlowBus Modbus
Float RW  0…1E+10 169 114/23 0xF2B8…0xF2B9/62137…62138
PID controller differentiation action in seconds. The default value is 0.0. This value should not be changed.
Open from Zero control response (Kopen)
Type Access Range FlowDDE FlowBus Modbus
Unsigned char RW  0…255 165 114/18 0x0E52/3667
Controller response when starting-up from 0% (when valve opens). Value 128 is default and means: no correction.
Otherwise controller speed will be adjusted as follows:
− = ⋅ (128 )
New response Old response 1.05 Kspeed
Normal Step response (Knormal)
Type Access Range FlowDDE FlowBus Modbus
Unsigned char RW  0…255 72 114/5 0x0E45/3654
Controller response during normal control (at setpoint step). Value 128 is default and means: no correction.
Otherwise controller speed will be adjusted as follows:
− = ⋅ (128 )
New response Old response 1.05 Knormal
Stable Situation control response (Kstable)
Type Access Range FlowDDE FlowBus Modbus
Unsigned char RW  0…255 141 114/17 0x0E51/3666
Controller response when controller is stable (within band of 2% of setpoint). Value 128 is default and means: no
correction. Otherwise controller speed will be adjusted as follows:
− = ⋅ (128 )
New response Old response 1.05 Kstable
4.1.6 Display filter
The output signal of an IQ + FLOW® instrument (measured value) is filtered. The filter has dynamic behaviour: when a
change in sensor signal is detected, the measured value will be less filtered than when the sensor signal is constant
and stable. There are two filter constants: Static Display Factor and Dynamic Display Factor. These two factors can be
transformed into time constants using the following formula:
factor
cycletime
factor
1
τ
−
= ⋅
The measured value is filtered with a first order low pass filter with a filter time constant between the two τ values.