Bronkhorst®
Instruction Manual EL-PRESS™
9.17.101I
33
Setpoint
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
Unsigned int
RW
0…32767
9
1/1
0x0021/34
This parameter is used to set the required flow rate for the controller. Within the setpoint range, value 32000 corresponds to
100%
Controller Hysteresis
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
Float
RW
0…1
361
114/15
0xF278…0xF279/62073…62074
This parameter is only used by P-800 series instruments (see
Process Pressure Controller (P-800 series)
). It defines a pressure
band around the setpoint where both control valves stay closed. This state becomes active when the setpoint is reached
and remains active as long as the measured pressure remains within the specified bandwidth.
The supported value range corresponds with 0 to 100% of the setpoint range. The default value is 0.001 (0.1%).
In case of control valve oscillation during operation,
Controller Hysteresis
can be increased gradually until control behavior
stabilizes.
4.2.1
Advanced measurement and control
Fmeasure
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
Float
R
-3.4E+38…
3.4E+38
205
33/0
0xA100…0xA101/ 41217…41218
Floating point variant of
Measure
.
Fmeasure
shows the measured value in the capacity unit for which the instrument is set.
The instrument uses parameters
Capacity
,
Capacity 0%
,
Capacity Unit
and
Sensor Type
to calculate
Fmeasure
.
Fsetpoint
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
Float
RW
0…3.4E+38
206
33/3
0xA119…0xA11A/ 41241…41242
Floating point variant of
Setpoint
.
Fsetpoint
shows the setpoint in the capacity unit for which the instrument is set. Like
Fmeasure
,
Fsetpoint
is dependent of
Capacity
,
Capacity 0%
,
Capacity Unit
and
Sensor Type
.
Setpoint Slope
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
Unsigned int
RW
0…30000
10
1/2
0x0022/35
The value of this parameter represents the time it would take to adjust the setpoint if it were changed from 0 to 100%. This
feature can be used to smooth 'nervous' controller behavior, e.g. to reduce setpoint overshoot or undershoot.
The supported range corresponds to 0…3000 seconds. Default value = 0.
Example:
If
Setpoint Slope
= 100 it will take 10 seconds to adjust the setpoint if it is changed from 0 to 100%. A setpoint change of 20%
will take (20%/100%)*10 seconds = 2 seconds.
Analog Input
Type
Access
Range
FlowDDE
FLOW-BUS
Modbus
Unsigned int
R
0…65535
11
1/3
0x0023/36
This parameter contains a digital translation of the analog input signal (if applicable).