DVC5000f Series Discrete Signal
FIELD_VAL_ D
Alarm Alarm Detection Detection
OUT_ D
Invert Option
PV_D
Invert Option
MODE
SIMULATE
Figure D-2. Discrete Input Function Block Schematic
transducer block parameters used with DI block channels 3 though 6. Section 4 describes the transducer block travel alerts.
DISCRETE INPUT CLEARED
Table D-2. Transducer Block Parameters Used with Discrete Input Function Block Channels 3 through 6 (Variable Limit Switch)
D
TRIGGER POINT FOR DOWNWARD VALVE TRAVEL DETERMINED BY TRAVEL ALERT DEADBAND
Parameter Function
Tvl Lo Lo Alrt Pt
Lo Lo Limit Switch trip point
Tvl Lo Lo Alrt DB
Lo Lo Limit Switch deadband
Tvl Lo Alrt Pt
Lo Limit Switch trip point
Tvl Lo Alrt DB
Lo Limit Switch deadband
Tvl Hi Alrt Pt
Hi Limit Switch trip point
Tvl Hi Alrt DB
Hi Limit Switch deadband
Tvl Hi Hi Alrt Pt
Hi Hi Limit Switch trip point
Tvl Hi Hi Alrt DB
Hi Hi Limit Switch deadband
Valve Position
Transducer Block Parameter
DEADZONE, 1% OF TRAVEL
CENTER POINT OF PROXIMITY DETECTION DETERMINED BY TRAVEL ALERT POINT
DISCRETE INPUT SET
TRIGGER POINT FOR UPWARD VALVE TRAVEL DETERMINED BY TRAVEL ALERT DEADBAND
Valve Position Proximity Detection Channels 7 through 10 provide valve position proximity detection for the DI block. The transducer block Travel Alrt Pt and Travel Alrt DB parameters are also used with the valve position proximity, but they provide a different function. The Travel Alrt Pt for the selected channel determines the center point for the position to be detected. The Travel Alrt DB for the selected channel sets the upper and lower trigger points, or the width of the proximity detection band. A 1% deadzone exists above and below this band that the travel must
D-2
Figure D-3. Discrete Input Proximity Detection Function
exceed to clear the detected position. Figure D-3 illustrates the operation of the proximity detection function. Travel Alrt Pt refers to Tvl Lo Alrt PT, Tvl Hi Alrt Pt, Tvl Lo Lo Alrt Pt, and Tvl Hi Hi Alrt Pt in table D-4. Travel Alrt DB refers to Tvl Lo Alrt DB, Tvl Hi Alrt DB, Tvl Lo Lo Alrt DB, and Tvl Hi Hi Alrt DB in table D-4. September 2000