SEO SEV PCS CENTRAL UNIT
The SEV SY1 AA PCS CENTRAL UNIT directs one serial line, the SEV SY2 AA PCS CENTRAL UNIT directs two serial lines (loop 2500 m), up to a maximum of 254 devices (sirens, call points and other accessories) by means of signal concentrators.

1. The signal concentrator is an interface module between the siren and the central unit; it is equipped with a line separator and can control 4 incoming and 4 outgoing signals.
The signal concentrator of a call point has only one NO input.
The central unit “interrogates” signal concentrators, integrated in sirens and call points that reply accordingly.
If a greater number of points must be managed, more CENTRAL UNITS SEV SY are required. They can be networked together and controlled by the CENTRAL UNIT defined as primary.

2. At the time of planning the installation, therefore, the number of concentrators in each device must be taken into consideration: SIREN (1 x 4 IN-4OUT), CONTROL BOX (4), CALL POINTS (1) and calculate: e.g. 20 sirens and 30 call points = 50 concentrators
3. The PCS CENTRAL UNIT carries out a constant control of the serial devices at four levels, even when they are not activated:
• AVAILABILITY OF MAINS POWER (24 hours constant control)
• BATTERY EFFICIENCY (one control every 24 hours)
• SIRENS WORKING (one control every 24 hours)
• LINE INTERRUPTION (24 hours constant control)

Parameter Name	Parameter Value