Siemens LC 500 Manual De Usuario

7ML19985GE01

SITRANS LC 500 – INSTRUCTION MANUAL 

Page 13

3.

Upper Threshold Setting and Lower Threshold Setting activate and deactivate the 

2-state output, and/or the solid-state output: the settings can be modified to adjust 
the hysteresis (the window within which the probe is considered ‘covered’).

4.

The speed of response to activation and deactivation of the solid-state and/or 

2-state output can be modified by Upper and/or Lower Threshold delays.

5.

The PV reading can be stabilized if necessary by applying Damping.

6.

Overfill or underfill protection can be set in the absence of those conditions by 

applying the Delta Range Setting.

7.

Analog Fault Signalling (menu 08) and Digital Fault Signalling (menu 18) take 

precedence over the threshold settings (menus 07 and 17).

The continuous 4-20 or 20-4 mA signal is proportional to the surface level of the product, 
with an accuracy of 0.1% of the actual measurement (for example, 1mm/m).

Typically, Lower Range Value (LRV - 0%) is set to 4 mA and Upper Range Value (URV - 
100%) is set to 20 mA: but the reverse is possible if required. The measurement takes 
place anywhere within that range. The LCD displays the value as mA, or pF, or percent, 
depending on the setting for the transmitter variable (TV). If you are using HART, you have 
the option to define the units. 

Indicator - dynamic Primary Variable (units or % of range)

0-100%

auxiliary 

power

pump 

power

solid-

state 

output

current loop connection

URV = 100% 

Upper Threshold Setting = % 

(activation hysteresis)

(deactivation hysteresis) 

Lower Threshold Setting = %

LRV = 0%

USL

LSL

solid-

state 

switch 

output

 or 

2-state 

mA output

Active Shield section

operationLC500.fm  Page 13  Monday, January 27, 2003  6:22 PM