Product Interfaces; Process Interface; Host Interface; Local Interfaces, Jumpers, And Switches - MSA General Monitors OBSERVER-i User Manual

4.0 PRODUCT INTERFACES

4.1

PROCESS INTERFACE

This section describes all interfaces between the devices and the measured process.
4.1.1 Sensor Input Channels
A digital display provides indications and display codes that can be viewed through a window on the
Observer-i. An analog signal (4-20 mA) and relays provide remote and/or discrete indications of the
detector's operation.
4.2

HOST INTERFACE

The HART interface uses the 4-20 mA (analog output) current loop. Refer to the Observer-i Installation
Manual for connection details.
4.2.1 Analog Output
The primary variable is proportional to the decibel (dB) sound pressure level (SPL). 4.0 mA output
current corresponds to <40 dB. 20.0 mA output current corresponds to 120 dB.
4.3

LOCAL INTERFACES, JUMPERS, AND SWITCHES

4.3.1 Local Controls and Displays
Refer to the Observer-i Installation Manual for connection details.
4.3.2 Internal Jumpers and Switches
Refer to the Observer-i Installation Manual for connection details.
5.0

DEVICE VARIABLES

There are no device variables available to the user.
6.0

DYNAMIC VARIABLES

There is only one Dynamic Variable available to the user.
6.1

PRIMARY VARIABLE = DECIBEL (dB)

The primary variable (PV) is proportional to the decibel (dB) SPL. 4.0 mA output current corresponds to
<40 dB. 20.0 mA output current corresponds to 120 dB.
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OBSERVER-i HART