MKS T3PIA, Instruction Manual, Page: 39 / 70

Trip Points Chapter Three: Product Overview
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Trip Point Direction
The trip point polarity, or direction, defines the direction of pressure change that will energize the trip point.
The direction of the trip points can be adjusted with a digital command, as described in
Trip Point Direction
in the MKS Type T3BIA/T3PIA Valves with RS-232 Interface Supplement.
The initial direction for all of the trip points is “low.” The trip point is energized and the trip point LED
illuminates as the pressure falls
below the specified trip point value. The trip point is not de-energized and the
LED is not cleared until the pressure rises above the value defined by the corresponding trip point hysteresis,
as shown in Figure 11.
Pressure
TRIP POINT
HYSTERESIS
TRIP POINT
VALUE
Trip Point
Condition
Trip Point Status OFF
Trip Point
Delay
Trip Point Status ON
Figure 11: Trip Point Direction Set Low
The direction for any of the trip points can be changed to “high.” The trip point is energized and the trip point
LED illuminates as the pressure rises
above the specified trip point value. The trip point is not de-energized
and the LED is not cleared until the pressure falls below the value defined by the corresponding trip point
hysteresis, as shown in Figure 12.
Pressure
TRIP POINT
HYSTERESIS
TRIP POINT
VALUE
Trip Point
Condition
Trip Point Status OFF
Trip Point
Delay
Trip Point Status ON
Figure 12: Trip Point Direction Set High