Installation manual

Engineering - 57
Watchdog:
The Watchdog is an additional device that can be purchased with the SMARTCASTER. It is an
electronic device which monitors the SMARTCASTER for lockups. The SMARTCASTER sends an
electronic pulse to the Watchdog every so often. If at any time, this pulse train stops, the Watchdog
assumes the SMARTCASTER has locked up. It then tries to rectify the situation by resetting the
SMARTCASTER.
If after the first reset, the Watchdog still does not see any pulses from the SMARTCASTER, it then resets
the computer again. If, after the second reset, the Watchdog still does not see a pulse train, it assumes
that something is horrifically wrong. It first closes a relay in order to trip a backup audio source. Next, it
closes a momentary relay in order to trip an optional autodialer. This autodialer can then call and alert
station personnel with an “off-the-air” emergency.
Installation
The Watchdog is packaged in a standard nineteen inch rack-mountable case. A 9VDC power supply is
provided. This should be plugged into the power jack in the back of the Watchdog.
Rear panel view of Watchdog
The Watchdog can actually monitor two SMARTCASTERS if needed. There are two 9-pin D-sub female
connectors on the back of each unit. These are labeled, “System-1” and “System-2”. Simply take the nine
conductor cable and connect one end to either “System-1” or “System-2”. Connect the other end to the 9-
pin connector on the SMARTCASTER labeled, ‘Watchdog’. (If modifying a SMARTCASTER in the
field, the connector needs to be installed in the SMARTCASTER. See below.)
Note: If the Watchdog is only used for one SMARTCASTER, you must use the “System-1” connection.
Next, the contacts to trip the autodialer and to start the backup audio source have been brought out to a
terminal strip on the back of the Watchdog. ‘Call’ 1 & 2 can be used to trip any typical autodialer used
for home security. These dialers, upon a momentary short from the ‘Call’ contacts, can call multiple
numbers and playback a recorded announcement.
Finally, the normally open, (NO), normally closed, (NC), and common, (C), contacts to start a backup
audio source are available on the back of the Watchdog. There is a set for both System 1 and System 2.
These contacts can be used to start some sort of backup device such as a reel-to-reel or cart machine.