Burkert 8792 Operating Instructions Manual page 133

Type 8792, 8793
Start-up, operation
process controller Type 8793
ENTER
PV SCALE
EXIT
* If the sub-menu is left by pressing the selection key on the left (ESC), the value remains unchanged.
** This setting specifies the reference range for the dead band of the process controller as well as for the analogue
feedback of the process actual value (option).
Fig. 77: Operating structure P.CONTROL - PV-SCALE - 4 – 20 mA
Scaling.example.of.the.4.–.20.mA.input
Process actual value from the transmitter:
Process set-point value from PLC:
Scaling value
Process actual value
[l/min]
10
0
4
Fig. 78: Scaling example
For SP INPUT internal (set-point value default via the arrow keys) the scaling of the set-point value via SPmin
and SPmax is not possible. The set-point value can be input directly according to the scaled process variable
(PVmin, PVmax ).
INPUT
PVmin 0.0 bar
*
OK
INPUT
PVmax 100.0 bar
*
OK
4 – 20 mA corresponds to 0 – 10 l/min
4 – 20 mA corresponds to 0 – 8 l/min
Process set-
point value
Input signal
[mA]
20
+
PVmin 0.0
Settings:
←
1. Specify the unit for the process actual value (bar,
mbar, psi, %, mm, litre, l/s, l/min, l/h, m³/min, m³/h,
UG/s, UG/min, UG/h, IG/s, IG/min, IG/h, °C, °F,
without unit).
2. Position the decimal point.
3. Set the lower scaling value for the process actual
value; the value is assigned to 4 mA**.
+
PVmax 100.0
Set the upper scaling value for the process actual
←
value; the value is assigned to 20 mA**
Example of inputting scaling values
Variant 1
PVmin 0
PVmax 1.0
SPmin 0
SPmax 0.8
english english
Variant 2 Variant 3
0 0
10.0 100.0
0 0
8.0 80.0
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