12
Testing and Faults
Positive Monitoring.
TheatreCue has been designed to continuously check for, and signal, any
possible fault condition. This means that operators are provided with the
maximum possible advance warning if there is any risk that a cue cannot
be given. As an example, all feedback given by the Main Unit is driven
entirely by the Outstations themselves. The ‘Standby’ and ‘Go’ buttons on
the Main Unit therefore will not illuminate unless the respective Outstation
has signalled to the Main Unit to do so. This ensures that not only com-
plete cable or Outstation failures can be detected instantly but intermittent
or ‘noisy’ circuits likely to impair the optimum performance of TheatreCue
will be detected and the operator alerted.
Fault LED.
The fault LED on each channel of the Main Unit can be in either of 3
states; ON (continuously), OFF or FLASHING. If all connections and sys-
tem functions are normal, the fault LED will remain OFF. If there has never
been an Outstation connected to that channel since initial power up, the
fault LED will remain ON continuously. If no signal can be received from
an Outstation, there is an intermittent or ‘noisy’ connection or an Outsta-
tion has been unplugged, the fault LED will FLASH. Once the source of
the fault has been identified and rectified, power down the Main Unit, wait
10 seconds then power it up again. Test the channel again by sending
several cues to the Outstation. If the fault LED remains OFF, the fault has
been cleared. If it remains ON continuously, the Outstation has become
completely disconnected. If it is still flashing, a fault still exists.
Short LED.
If there is a short circuit anywhere on the Outstation circuit; power is re-
moved from all Outstations, the system will commence testing at between
2 and 8 second intervals to see if the short has been cleared and the
‘Short’ LED will illuminate continuously. Whilst in this state, all cabling and
connections can be checked ‘live’ to see when the fault clears and the
‘Short’ LED goes out.
