Endress+Hauser Liquisys M CUM253 - Current Outputs Configuration

Commissioning Liquisys M CUM223/253
40 Endress+Hauser
6.4.4 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 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 via the current output.
a0003170
Fig. 23: User defined current output characteristic
The current output characteristic must be strictly monotonously increasing or strictly
monotonously decreasing.
The distance per mA between two table value pairs must be greater than:
• 0.005 FNU / NTU / ppm mg/l / %
• 0.05 g/l
• Temperature: 0.25 °C
The values for the sample characteristic ( å 23) are entered in the following table. The
distance per mA can be calculated from  signal /  mA.
6000
3000
9000
0
0 48 121620
DI [mA]
I [mA]
D Signal
FNU
Current output 1 Current output 2
Value pair Tu / °C Current
[mA]
Distance
per mA
Tu / °C Current
[mA]
Distance
per mA
104
2 3000 16 250
3 9000 20 1500