Status Indication; Switch Functions - Emerson MRLDS-450 Installation And Operation Manual

4.1.4. Status Indication

The MRLDS-450 gas detections provide external indication of its current
operational state via audible and visual feedback. Visual indication of the instrument
status is provided by a single tri-color LED (Green/Red/Orange). MRLDS-450 gas
detection instruments also provide relays outputs. Instrument states and
corresponding outputs are shown in Table 4-4.
State
Warm-up
Normal
Low Alarm
High Alarm
Offline
Fault
Negative Gas Fault
Zero Cal. Fault
Span Cal. Fault
Table 4-4 - Status Indicators

4.1.5. Switch Functions

User interaction with the MRLDS-450 gas detector is accomplished through the use
of two magnetic switches located on the bottom of each unit. To actuate a magnetic
switch, apply the supplied magnetic wand to the relevant switch location as shown
in Figure 4-1.
Overview of Normal Operation
LED Buzzer
Relay 1 Relay 2
(LOW) (HIGH)
OFF OFF
OFF OFF
ON OFF
ON ON
OFF OFF
OFF OFF
OFF OFF
OFF OFF
OFF OFF
Relay 3
(Fault)
OFF
OFF
OFF
OFF
OFF
ON
ON
OFF
OFF
Operation • 15