71
Basic setting of the process controller
Type 8792, 8793 REV.2
15.2.2.1.
Effects and dependencies of the settings of
PV-INPUT
on
PV-SCALE
The settings in the
PV-SCALE
menu have different effects, depending on the signal type selected in
PV-INPUT
.
Even the selection options for the units of the process actual value (in
PVmin
) depend on the signal
type selected in
PV-INPUT
.
See following “Table 40”
Settings in the
submenu of
PV-SCALE
Description of the effect
Dependency on the signal type selected in
PV-INPUT
4 - 20 mA
PT 100
Frequency
PVmin
Selectable unit of the process
actual value for the physical
variables.
Flow rate, temperature,
pressure, length, volume.
(as well as ratio as% and
no unit)
Temperature Flow rate
Adjustment range:
0...9999
(temperature -200...800) -200...800
0...9999
PVmin
PVmax
Specification of the reference
range for the dead band of the
process controller
(
P.CONTROL
→
PID.PARAMETER
→
DBND).
Yes
Yes
Yes
Specification of the reference
range for the analog feedback
(option).
See chapter “26.2.14. OUTPUT
– Configuration of the outputs
(option)”.
Yes
Yes
Yes
Sensor calibration:
Yes
see “Figure 37”
No
No
K factor
Sensor calibration:
No
No
Yes
see
“Figure 38”
Adjustment range:
–
–
0...9999
Table 30:
Effects of the settings in PV-SCALE depending on the signal type selected in PV-INPUT
Example of a sensor calibration for the
4 - 20 mA
signal type:
Scaling value
[l/min]
Input
signal [mA]
Process set-point
value
Process actual value
4
0
10
20
PVmin
SPmin
PVmax
SPmax
Scaling:
Process actual value from the transmitter:
4...20 mA corresponds to 0...10 l/min
Process set-point value from PLC:
4...20 mA corresponds to 0...8 l/min
Figure 27:
Example of a sensor calibration for the 4 - 20 mA signal type
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