Emerson Process Management ControlWave EFM 3808 - Manual (Page 35)

CI-ControlWave EFM Introduction / 1-19
modem will mount via a Radio/Modem Mounting Bracket (beneath the Battery Mounting
Bracket on units equipped with a 4-Slot Chassis)..
1.3.9 Multivariable Transducer
The Multivariable Transducer (MVT) pressure assembly is connected to the process
manifold either directly or by tubing. In the body of the transducer, metal diaphragms are
exposed to the gas. Solid-state strain gauge sensors in the neck of the transducer measure
the pressure applied to the diaphragms and produce proportional electrical signals.
The neck of the Multivariable Transducer extends into the bottom of the enclosure, with the
body of the transducer outside the enclosure. The MVT cable connector is factory mated
with System Controller Module connector P2.
1.3.10 Power Distribution Board
When an external power source is used to provide bulk power to the unit, power is routed to
various optional items through a Power Distribution Board. In this case, options such as
the 21V Power Supply, Digital to Relay I/O Board or an external radio or modem, will
require the use of the Power Distribution Board. Power Distribution Boards, Digital to
Relay I/O Boards and the 21V Power Supply Boards are mounted to the inside of the
enclosure in question using a Snap Track and Dual PCB Mounting Bracket.
Figure 1-10 - Power Distribution Board
1.3.11 Digital to Relay I/O Option
The Digital To Relay I/O Board (see Figure 1-11) converts one or two Discrete Output
Signals from open drain MOSFET levels to Form C relay output signal using Solid State
Relay (SSR) logic.
Each Discrete Output can be converted to Form C relay output signals which can be
configured for opposite or identical conditions, i.e., both Normally Open (NO) or Normally
Closed (NC) or one Normally Open with the other normally Closed.