The ATU-8 ALARM TRANSMITTING UNIT and the ARU-8 ALARM RECEIVING UNIT together make up an 8 channel alarm and control Superhighway which can provide up to 160 alarm and control channels on any one video signal. The alarm and control signals are inserted into the Vertical Interval of the video signal so that they will not interfere with the picture. When the video signal is recorded, the alarm and control information is also recorded and can be recalled at play-back. Alarm and control signals will be correlated with the video events. Each pair of ATU-8 / ARU-8 will transmit 8 alarms. Twenty sets of units may be connected to any one video channel, allowing 160 alarms to be transmitted on one coaxial cable. The operating channel can be set by the user in the field with the internal program pumper Jacks. A system alarm will operate upon loss of power to either terminal or loss of transmission path (cable cut). In the event of power failure the video thru-put is not interrupted. An internal video sync generator takes over and maintains continuous alarm system operation in the event of video signal failure. Contact closures to the ATU-8 input will be repeated as contact closures at the ARU-8 output. The system is housed in black ABS enclosures that have a UL flame rating of 94-VO and is powered by 24VAC power transformers.The system has provisions for battery back-up and LED power indicator lights to help installation.