MKS Baratron 740C, Manual, Page: 61 / 84

Chapter Five: Type R7xxC Relay System General Information
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Chapter Five: Type R7xxC Relay System
General Information
The Type R7xxC pressure relay system consists of a 74xC or 75xC transducer attached to a relay
module. The relay module provides two alarm trip points, two relays, and two status LEDs. The
pressure transducer functions exactly the same as units without the relay module. Refer to
Chapter Three: Overview, page 46, for a description of the pressure transducer.
Initial Settings
The relay module enables you to select the pressure condition that will energize, or activate, each
relay. You can configure the module to energize a relay when the pressure drops below the trip
point, or when the pressure rises above the trip point. Each relay functions independently. The
initial configuration is described in Table 21.
Initial Settings for the Relay System
Parameter Setting
Trip Point A State
Setting
Energized below the trip point setting
55% F. S.
Trip Point B State
Setting
Energized above the trip point setting
55% of F.S.
Table 21: Initial Settings for the Relay System

Trip point A is energized below the trip point (it is de-energized when the pressure is
above the trip point value and it is energized when the pressure falls below the trip point)

Trip point B is energized above the trip point (it is de-energized when the pressure is
below the trip point value and it is energized when the pressure exceeds the trip point)
You can change the trip point values by turning the trip point adjust pots on the side of the unit.
Note
The trip point adjustment voltage ranges from 0 to 10 Volts,
corresponding to zero to full scale.