The Essex Model 2404 Annunciator is designed to monitor Alarm Contacts and provide "point" indication on the device which is alarming.  The standard unit comes equipped to monitor two remote points, but can be optionally equipped to accommodate four points.

Each point has a selector switch located on the 2404 drawout PC board, which will allow the point to be set up to monitor a normally open, or normally closed contact.  A lock-in/nonlock-in switch is also provided on the PC board for each point.

On lock-in or non-lock-in, the alarm indication flashes until acknowledged, whereupon it will light continuously until the field condition is corrected.  In lock-in status, the alarming point must be acknowledged before it will reset.  In the nonlock-in status, the unit will cease to alarm if the point being monitored returns to normal.

An auxiliary output NPN transistor is standard for each alarm point.  Transistor follows activation of the field input contact.

An optional 0.1 to 60 second time delay is available on the input circuit.  This avoids unnecessary alarm indication for those conditions which may be only momentary.