Product Manuals/Man-1088_Sigma XT_26 Page 30 of 40
18. Internal Controls
18.1 Watchdog reset
If for any reason the microprocessor in the control panel fails to carry out its operation correctly it
will attempt to restart itself. This process is called a “watchdog” and the control panel must record
and indicate these events.
If a watchdog event occurs, the control panel will show the FAULT and SYSTEM FAULT LEDs on
the front panel, the CPU fault LED inside the panel and the buzzer will sound. This fault can only
be cleared by pressing the WATCHDOG RESET button on the PCB inside the control panel. This
is a serious failure and the control panel buzzer will continue to sound until the watchdog
activation is reset.
18.1 Processor reset
Once started, the microprocessor controlling the panel should continue to run the panel
continuously without interruption. If the microprocessor fails to run correctly it can be reset by
pressing the PROCESSOR RESET button on the PCB inside the control panel.
This should not normally be necessary but should be done as a matter of course if the system is
behaving abnormally. The system should resume normal operation within a couple of seconds of
pressing the processor reset button.
18.3 Terminate extinguishant
Once the release output has been initiated it can not be stopped using the reset button until after
the extinguishant duration timer has elapsed. For test purposes a terminate extinguishant button is
provided at access level 3 which will terminate an already running extinguishant flooding and allow
the system to be reset to normal.
18.4 Commissioning
Changes to the configuration as listed in table 5 require that the changes be stored in the control
panel memory. To enable the memory to be written to it is necessary to operate the Write Enable
slide switch.
Figure 18 – Terminate Extinguishant, Watchdog reset, Processor Reset and Write enable switches
TELL
TALE
EXTING
W/DOG
RESET
RESET
WRITE
ENABLE
PROC
.
TERMINATE
