
ST750
G
ENERAL
H
ANDBOOK
667/HB/33750/000
Page 106
Issue 6
8. SELF-TEST FACILITY
The self-test facility can be used to check the hardware fitted to the controller, even
before a configuration is loaded. It is designed to be used both in the factory by
production and on the street by installation/ maintenance engineers.
Self-test is initiated by holding down the level 3 access button while switching on the
power to the controller. The button should be released once the green heartbeat
LED starts to flash.
The green heartbeat LED continues to flash during the self-test unless a fault is
detected when the red system error LED illuminates.
Connecting a 20 character by 4 line handset displays information about the checks it
is performing, such as the firmware issue and the lamp supply voltage, both dim and
bright, and detail any faults found.
Self-test performs the checks detailed on the following pages and produces error
messages if faults are detected.
While the self-test is running, the manual panel can be checked. Pressing each
button on the panel should illuminate the associated LED. To distinguish this from
normal operation, the LED flashes at a fast rate while the button is depressed. Note
that the ‘Lamp Test’ button illuminates all the LEDs, as it does for normal operation.
To test the signals on/off switch and the cabinet alarm LED, switching the switch to
the signals ‘on’ position illuminates the cabinet alarm. Switching it to the ‘off’ position
extinguishes the cabinet alarm indicator. Note that the signals on/off switch does not
affect the self-test in any other way.
•
Resolving problems with lamp switch cards and triacs:
When various tests fail, the handset may display information such as:
No voltages on:
identifies the test which has failed
R-000000000
outputs from the red voltage monitors
A-000000002
outputs from the amber voltage monitors
G-000000000
outputs from the green voltage monitors
-ve Peak +ve Peak
The numbers are in hexadecimal notation and so each of the eight digits encodes
four phases, as follows: