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Multi-Point Process Switch
EX-1711
Set-Points/Deadband Adjustments
Set-Points
The Process Switch has four (4) user set-points which are
continuously adjustable over the full 4-20 mAdc input
range. Each set-point can be adjusted to within 0.008
mAdc (or 0.05% FS).
Coarse Adjustment
—20-turn potentiometer/each
complete turn yields approximately 1.0 mA change.
Fine Adjustment
—20-turn potentiometer/each
complete turn yields approximately 0.005 mA
change.
Deadband
A master deadband adjustment controls all four set-points.
The deadband adjustment range is 1.0% -12.5% FS. (Process
Switch is factory-preset with a nominal 1.0% FS deadband.)
Deadband can be used to eliminate cycling due to
fluctuations within the 4-20 mA input signal. Resetting the
deadband will also shift the set-point accordingly. Refer to
diagrams below:
10.00 mA
9.84 mA
Set Point
1% FS
Deadband
Relay
Remains
Energized
Relay off
Relay is
triggered
mA
mA
10.00 mA
10.04 mA
9.84 mA
9.80 mA
Original
Set Point
Increased
Deadband
Relay
Remaining
Energized
Relay off
Relay is
triggered
mA
mA
16.00 mA
15.68 mA
Set Point
2% FS
Deadband
Relay
Remains
Energized
Relay off
Relay is
triggered
mA
mA
15.96 mA
16.00 mA
15.72 mA
15.68 mA
Original
Set Point
Decreased
Deadband
Relay Remaining
Energized
Relay off
Relay is
triggered
mA
mA
Decreased Deadband Effect on Set-Point
Increased Deadband Effect on Set-Point
