KROHNE BM 70 A_P EN - Manual (Page 61)

Installation and operating instructions BM 70 A/P Page: 61 11/00
Group S Switching output
No. Fault / Symptom Cause Corrective action
S1 Switching output does not operate
at the desired limit value (threshold)
or does so in the wrong mode
(opens/closes). Setting of switching function is
incorrect. Set switching output correctly as
described in Sect. 8.6.17 (Fct. 3.6.1 -
3.6.4).
S2 Switching output does not operate. Switching output defective. Check switching output as described in
Sect. 8.7.4:
- Test OK: check setting and receiver
instruments.
- Test reveals faults: switching output
defective. Consult KROHNE Service
or replace BM 70 A/P signal converter
as described in Sect. 7.3.
8.11 Calculation of the measured value
The following describes how the individual items of information are calculated from the measured distance:
measured
(internal)
Offset
Distance
+
–
Level
+
tank height
Fct 3.1.1
–
conversion
table
+
+
+
+
Ref.Offset
Fct 3.1.7 TB Offset
Fct 3.1.8
Fct 3.2.1
display
BM 70 local display
function
distance
BM 70
Fct 3.3.1
I output
BM 70 current output
function
BM 70 digital
communication
The measured primary distance is corrected by the offset and consequently standardized to the reference point
( = flange). The level is calculated as the difference between tank height and distance. Optionally, distance, level
or a converted function can be output to the signal output and the local display. All items of information can be
accessed via the digital Communication. In addition, the measured value can be shifted by a reference offset
(reference point for distance not equal to flange) or by a tank bottom offset (reference point for level not equal to
tank bottom).