Analog Output Scaling - Siemens LR250 Instruction Manual

2.6. Analog Output Scaling

2.6.1. Current Output Function
Notes:
• Level, space, and distance, have different reference points.
• Use caution when changing Current Output Function while the device is
connected to a HART network. Current Output Function controls the
primary value and the loop current for the device.
• Current Output Function also affects the secondary, tertiary and
quaternary variables in a HART network.
Can be set to either Level, Space, Distance, or Volume. (The device can carry
out a volume calculation only after a vessel shape has been specified.)
Level
Sensor
ref.
pt.
High
Cal.
Point
Low
Cal.
Pt.
Options
* Level
Space
Distance
Volume
Manual
(LUI only)
a)
Current Output Function must be set to Manual before modifying mA Output Value
(2.6.6.). Remember to restore the previous Current Output Function setting after
modifying mA Output Value.
To view the mA reading in the secondary region of the LCD, press
handheld programmer.
To modify Current Output Function via SIMATIC PDM:
• Open the menu Device – Select Analog Output. (See
on page 56 for more detail).
7ML19985JE06 SITRANS LR250 (HART) – INSTRUCTION MANUAL
Space
20 mA
100%
Level
4 mA
0%
Reference point
Low Calibration Point
High Calibration Point
sensor reference point
converts a level measurement to a volume output
a)
allows mA Output Value (2.6.6.) to be set to a user-defined value
Distance
4 mA
0%
Space
20 mA
100%
Description
measured as a percentage of the
difference between High Calibration Point
and Low Calibration Point
measured as a percentage of Low
Calibration Point
4 mA
0%
Distance
20 mA
100%
on the
Select Analog Output
Page 87