LaserSCANNER Product Manual
VESDA
®
20
General Purpose Input (GPI) Functions
The input terminal requires a voltage supply between 5V and 30 VDC to operate. The input is
isolated from the system by an opto-coupler device. Connect the GPI + terminal to the positive
output and the GPI - terminal to the ground output of the external device. The GPI can be
configured to initiate a number of different actions - including, by default, a Remote Reset
function. The GPI can be configured through the ‘Miscellaneous’ screen menu of the LCD
programmer. See the LCD Programmer Manual for details.
Function
State change
External
Reset
Detector Reset when
≥
5 VDC is at
this terminal.
Mains OK
The detector monitors the state of
the external power supply and
responds to the following
conditions.
Mains OK
≥
5 VDC at this terminal
Mains Fail
≤
2 VDC at this terminal
Standby
Mode
The detector Isolates and the
aspirator turns OFF when
≥
5 VDC
is at this terminal
Note:
No Alarms can be
generated in this state
Isolate
The detector isolates when the
voltage rises above 5 VDC and De-
isolates when the voltage falls
below 5V.
Use
Night-time
Threshold
The detector switches over from
day-time to night-time thresholds
when
≥
5 VDC are at these terminals.
Day Night Day
Reset+
Isolate
While power is applied to the GPI
the detector is isolated. In addition,
the disconnection or connection of
power to the GPI resets the unit.
≥
5 VDC detector isolates
≤
2 VDC detector reset
Reset Isolated Reset
Reset
Mains Fault Reported