Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 11 Page 235 of 265
If either processor or the hardware watchdog shuts down the controller, with the
‘Non UK Links’ fitted, the following sequence occurs:
1. One Lamp Supply relay is released, switching off the lamp supply to all but the
first LSLS Card.
2. The other Lamp Supply relay is forced on;
3. The Dim/Bright Relay released to force signals to their ‘Bright’ state;
4. All the Red, Amber and Green phase output latches on the LSLS cards are
‘Reset’;
5. ‘Flash Oscillator’ output enabled onto the Phase Bus. This may have a “steady
on period” at the start.
6. All the signals connected to the first LSLS card flash.