Page 44
STT700 Series HART/DE Option User’s Manual
Revision 1
Online/Device
Setup/Advanced
Configuration/Sensors
Average
Average of S1 and S2
Redundant
When the LCM is configured in redundant
mode, the loop is initially controlled via Sensor
1.
Should any disconnection occur to Sensor 1
(such as a burnout), the loop control will
immediately switch to Sensor 2.
Should Sensor 1 be repaired after this time, the
LCM will wait 15 seconds and then switch loop
control back to Sensor 1.
This delay is to prevent an intermittent failure
on Sensor 1 from causing the LCM to rapidly
switch between Sensor 1 and Sensor 2.
Following a power-cycle or a resent, the LCM
will normally start up by using Sensor 1 to
control the loop. Should Sensor 1 be in a
failed condition, the LCM will immediately
switch to Sensor 2
Split Range
S1 ; for S1 < = MRV (Mid-Range Value )
S2 ; for S1 > MRV (Mid-Range Value)
Loop controlled by
Read only parameter
Displays the loop controlling sensor
Latching Alarm
Read only parameter
Delta Limit
Enter the desired limit value for the PV
Delta. When PV Delta exceeds the limit, the
PV Excess Delta Alarm will be triggered.
Excess Delta Detect
Read only parameter.
Select to Enable or Disable Excess Delta
Detection. When Enabled, an alarm will be
triggered when the Delta PV (Sensor 1-Sensor
2 difference) exceeds the configured Delta
Limit.
PV Delta
Read only parameter
The difference in measurement between
Sensor 1 and Sensor 2 (Sensor 1 value
–
Sensor 2 value)
Break Detect
Read only parameter
Select to Enable or Disable Sensor Break
Detection. It is highly recommended to keep
this option Enabled.
If there is a break or open in either sensor
input, and Break Detect is Enabled, a Critical
Status will be generated. If Break Detection is
Disabled, no Critical Status is set and the
input value will be unreliable.