MKS Baratron 631D, Инструкция по эксплуатации, Страница: 51 / 64

Chapter Five: Optional Solid-State Relay System
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Chapter Five: Optional Solid-State Relay System
General Information
The 631D transducer provides the option for two (2) internally mounted trip point relays with
user adjustable pressure conditions that will turn ON/OFF each solid state relay. The trip point
direction – whether the relay turns ON above or below the selected pressure condition – is chosen
using the appropriate model code when purchasing the 631D transducer (refer to Appendix B:
Model Code Explanation, page 51). A visual indication of the status of each trip point relay is
provided by a dedicated LED that illuminates when the trip point relay is turned ON. The relay
gets turned OFF and the LED turns off when the pressure returns to the selected trip point value
plus hysteresis (refer to Trip Point Direction, page 44 for a description of how hysteresis affects
the relay switching).
The interface connector houses the contact pins of both trip point relays to equip the user with
remote indication of the relay status. The three pins of each relay produce an open/closed output;
for example, if Trip Point A is turned ON, pins 3 & 4 will be an open circuit. Refer to Table 6:
Pinout of the Interface Connector (J1), page 34, for the pinout of the Interface (J1) Connector.
Trip Point Parameters
Trip Point Values
The trip point value is the pressure condition that each relay will get turned ON. The trip point
value of each relay can be adjusted individually using the trip point adjustment POTs. These
POTs are located on the top of the 631D unit, as shown on Figure 8, page 44, and labeled as
“Adj” above the corresponding “Trip Pt A” and “Trip Pt B” label. The trip point value can be
monitored by measuring the voltage between the trip point signal of interest and the ground
(labeled as “Trip Pt. Signals” and “Gnd”). A pair of 0.080 inch test point jacks must be used in
order to gain access to the trip point voltage signals. The trip point signal voltage ranges from 0
to 10 V, which corresponds to the pressure range of the unit from zero to full scale.