Bronkhorst IQ+FLOW (from 01-07-2013) - Manual (Page 24)

Bronkhorst High-Tech B.V.
IQ+FLOW 9.17.045 24
Controller Speed (Kspeed)
Type Access Range FlowDDE FLOW-BUS 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 FLOW-BUS 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 FLOW-BUS 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 FLOW-BUS 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:
New response = Old response·1.05 (128-Kspeed)
Normal Step response (Knormal)
Type Access Range FlowDDE FLOW-BUS 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:
New response = Old response·1.05 (128-Knormal)
Stable Situation control response (Kstable)
Type Access Range FlowDDE FLOW-BUS 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:
New responce = Old responce·1.05 (128-Kstable)
4.1.5 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:
The measured value is filtered with a first order low pass filter with a filter time constant between the two ô values.