Endress+Hauser Liquisys M CPM223, Руководство по эксплуатации

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Liquisys M CPM223/253 Operation
Hauser 41
5.4.4 Current outputs
Use the "Current output" function group to configure the individual outputs. You can enter either
a linear characteristic (O3 (1)) or a user-defined current output characteristic in conjunction with
the Plus Package (O3 (3)). Exception: if you have chosen a "continuous controller" for current
output 2, you cannot enter a user-defined current output characteristic for this current output.
In addition, you can also simulate a current output value (O3 (2)) to check the current outputs.
If a second current output is present, you can output the controller actuating variable in accordance
with field R 237 / R 266 via the current output.
C07-CPM2x3xx-05-06-00-xx-004.eps
Fig. 35: User-defined current output characteristic (example)
The current output characteristic must be extremely monotonic increasing or extremely monotonic
decreasing.
The distance per mA between two table value pairs must be greater than:
• pH: 0.03
• Redox: 5 mV
• Temperature: 0.25 °C
The values for the sample characteristic (
→
Fig. 35) are entered in the following table. The distance
per mA can be calculated from
∆
signal /
∆
mA.
First enter the desired current output configuration into the following blank table with a pencil.
Calculate the resulting signal distance per mA to observe the necessary minimum slope. Then enter
the values in the device.
10
8
12
6
0 4 8 12 16 20
I [mA]
D
I [mA]
D
Signal
pH
Current output 1 Current output 2
Value pair pH / mV /
% / °C
Current
[mA]
Distance
per mA
pH / mV /
% / °C
Current
[mA]
Distance
per mA
1 6 4
2 8 16 0,166
3 12 20 1,000