VX-2004 & VX-2005 - Programme Fail Detectors

VX-2004

These Eurocard modules are designed to monitor video and audio signal continuity and provide alarm outputs in the event of signal loss. When used in conjunction with the VX-4026 relay modules or BCU-300 Broadcast Changeover Unit, programme feeds can be re-routed and backup procedures initiated.

The VX-2004 offers one or two channels of audio monitoring. The VX-2005 also offers one or two channels of monitoring, which may be factory configured for audio, video or one channel of each.

VX-2004 / VX-2005 block diagram

The detectors operate by measuring audio level or the level of video syncs, starting a fail timer if the signal level exceeds chosen parameters. If the timer trips before the signal returns to an acceptable level, then an alarm is signaled. If the signal returns to an acceptable level, the restore timer is started, causing the alarm to be terminated if the signal remains acceptable for the duration of the restore timer's run. This combination of controls avoids unnecessary alarms and ensures a good signal is present before canceling the alarm.

Specifications
VX-2004 (Audio Programme Fail Detector)
Inputs 2x line level 0dBu (nom), xformer isolated & balanced
Detector range -10dBu to -60dBu approx, adjustable
Fail timer range 0 to 60 seconds, adjustable
Reset timer range 0 to 60 seconds, adjustable
Relay output DPDT signal-quality changeover relay (1 per channel)
Aux logic inputs TTL level for immediate fail override (eg. codec fail)
VX-2005 (Video / Audio Programme Fail Detector)
Video inputs 1 or 2 composite 700mV, 75 ohm
Video detector range 0dBV to -12dBV
Video fail timer range 5ms to 5 seconds, set in steps
Video reset timer range 5ms to 5 seconds, set in steps
Audio inputs -10dBu to -60dBu approx, adjustable (per channel)
Audio fail timer range 0 to 60 seconds, adjustable (per channel)
Audio reset timer range 0 to 60 seconds, set in steps (per channel)
Relay outputs DPDT signal-quality changeover relay (1 per channel)
Aux logic inputs TTL level for immediate fail override (eg. codec fail)