Siemens SITRANS LR250 Operating Instructions Manual page 134

Parameter reference
Lower Limit Warning (2.6.7.3.)
The setting for the lower warning limit in AIFB1 units.
Values
Lower Limit Alarm (2.6.7.4.)
The setting for the lower alarm limit in AIFB1 units.
Values
Limit Hysteresis (2.6.7.5.)
Hysteresis is used to adjust the sensitivity of the trigger for alarm messages. It is used to
compensate when a process variable fluctuates around the same value as a limit. A high level
alarm occurs when a value exceeds an upper limit. The alarm's status remains true until the
value drops below the limit minus the alarm hysteresis. The directions are reversed for low limit
detection.
Values
Enter a value for the hysteresis here, to be used for all warnings and alarms. The units are the
same as the Output scale, i.e. AIFB1 units.
Display (2.6.8.)
Filter Time Constant (2.6.8.1.)
The time constant for the damping filter. The damping filter smooths out the response to a
sudden change in level. This is an exponential filter and the engineering unit is always in
seconds. See Damping (Page 239) for more detail.
Values
132
Range: -999999 to 999999
Default: -999999
Range: -999999 to 999999
Default: -999999
Range: -999999 to 999999
Default: 0.50
Range: 0 to 600 s
Default: 10 s
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 08/2014, A5E32221386-AC