We have multiple simplex inputs in CSLS's that have EOL resistor packs installed. During commissioning we tested for shorts/opens and found that the we were getting a BAD status on the output of the LSDI when either of these conditions was present. This lead to a TRIP condition. The clients desired behavior here would be to alarm on Line Fault Detected but NOT to trip. (these are not SIF's). We modified the settings in the LSDVTR but with a simplex input the "Do not vote if BAD" option still results in a trip.
To complicate things they also want some of these LSDI's to be ON to TRIP and some to be OFF to TRIP.
Any ideas on how to just alarm and inhibit the trip if a line fault is detected??
Hello ControlMech,
It may work differently based on the DeltaV Version, and CSLS Revision you're using, but the Bad Status will eventually start a countdown, leading to a TRIP.
For CSLS Rev1, the status will propagate the the Output Function Block (LSDVC/LSDO), having the FSTATE_OPTS configured to detect faults
Will trigger the FSTATE_TIMER, and the trip will occur once the FSTATE_TIME is fulfilled.
In a CSLS Rev2, this is handled at the DVTR/AVTR Function Block, once the bad status happens, the TRIP_INH_TIMER will start counting, and once the TRIP_INH_DELAY is fulfilled, the DVTR/AVTR output will trip.
On the TRIP type/direction, if you're using CSLS Rev2, you simply change the LOGIC_TYPE
For the CSLS Rev1, you might need to add custom configuration to handle the inversion properly.
Rgs,
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