Siemens 7ML5431 - Sensor Mode; Current Output Function

Appendix A: Technical reference
A.3 Analog Output
SITRANS LR250 with mA/HART
242 Operating Instructions, 10/2019, A5E32220602-AG
A.3.1 Sensor Mode
This parameter controls the input. Depending on the reference point used, the measurement
reports either Level, Space, or Distance. By default Sensor Mode is set to
Level.
Operation
Description
Reference point
NO SERVICE Measurement and associated loop current
not being updated. Device defaults to Fail-
safe mode
1)
.
LEVEL Distance to material surface Low Calibration Point (process
empty level)
SPACE Distance to material surface High Calibration Point (process
full level)
DISTANCE
Distance to material surface
Sensor reference point
1)
See Fail-safe Mode (Page 243).
You also have the option to put the device out of service, in which case the device defaults
to Fail-safe mode, and the reported level depends on the device type. A standard device
reports the last valid reading, and a NAMUR NE 43-compliant device reports the user-
defined value for Material Level (3.58 mA by default).
①
Sensor reference point
⑤
4 mA 0%
②
High calibration point
⑥
Distance
③
20 mA 100%
⑦
Level
④
Space
⑧
Low calibration point
A.3.2 Current Output Function
Current Output Function (2.6.1.) controls the mA output and applies any relevant scaling. By
default it is set to
Level. Other options are Space, Distance, and Volume. (The device can
carry out a volume calculation only after a vessel shape has been specified.)
When a volume application type is chosen, Sensor Mode remains as Level and the mA
Output is automatically converted to
Volume.
To view the mA reading in the secondary region of the LCD, press on the handheld
programmer.