KROHNE LEVEL-SONIC BM90 Series Installation And Operating Instructions Manual page 21

Pr. 30 Analogue Output (D=1)
Pr. 1 Entry
1.00
2.00
3.00
4.00
NOTE: Refer to Pr.34 for output test.
Enter 1 - 4-20mA )
2 - 20-4mA )
3 - 0-20mA )
4 - 20-0mA )
5 - 4-20mA )
6 - 0-20mA )
The output represents different variables depending on
the application mode selected at Pr.1
Limits are defined by Pr.4
Pr. 31 Analogue Value Options (D=1)
In differential mode (Pr.1 = 3)
Enter 1 - difference of two levels
- Pr.4 represents maximum differential in levels
2 - upstream level
- Pr.4 represents the difference between
upstream empty distance Pr.3 and maximum
upstream level.
3 - downstream level
- Pr.4 represents the difference between
downstream empty distance Pr.3 and
maximum downstream level.
In OCM mode (Pr.1 = 4)
Enter 1 - for measured head (depth of liquid)
2 - for calculated flow
Pr. 32 Analogue Datum (D=0.00)
If an analogue output is required with a zero different
from the measurement zero (Pr.3) then an offset defined
as a percentage of the measurement span/flow/volume
etc., can be entered here.
Application
Liquid Level
Distance
Differential (DLD)
Open Channel Meter (OCM)
> related to span (Pr.4)
or Pr.33
> will over-range 0-24mA
if normal span
(Pr.4) is exceeded
Output Proportional To
a) Liquid Level
b) Liquid volume if Pr.40 is used
a) Target distance
b) Space volume if Pr.40 is used
Differential level. (The unit can differentiate between
positive and negative differentials. (See Pr.31)
a) If Pr.31 = 1 output proportional to head
b) If Pr.31 = 2 output proportional to flow
Pr. 33 Analogue Span (D=100)
If an analogue output is required with a span different to
that defined for the measurement (Pr.4) then an alterna-
tive value defined as a percentage of the measurement
span/flow/volume etc., can be entered here. A value of
zero is ignored.
Pr. 34 Analogue Output Test (D=0)
This parameter can be used to examine the last analogue
output value set up by the instrument. Also any value in
the analogue output range can be entered for loading to
the current output, and can be measured at the output
terminals, to test the external analogue circuitry.
Pr. 37 Temperature Sensor Enable (D=1)
1 = No sensor attached
2 = Senor attached
Pr. 38 Compensating Temperature (D=20 C)
If no probe is fitted the vessel temperature may b entered
here.
Pr. 39 Temperature Probe test (D=0)
Displays the sensor resistance in K Ohms. Typically 9.5
at 20 C.
If value shows '0.00' after switching 'Off' and 'On' then
either no sensor is connected, or there is a short circuit or
open circuit in the system.
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