SMPTE 269M-1999

This standard describes a simple interface over which television equipment can report the occurrence of internal failures and faults in incoming signals. It is intended for use in all television equipment, from the simplest active devices to the most complex.The interface consists of an isolated closure which can assume one of three states: open, closed, or pulsing. These respectively signal that the reporting device is okay, has detected an internal fault, or is detecting incoming signal faults. Fault occurrence data may be collected from equipment complying with this standard by several means, ranging from simple "follow the lights to the trouble" summary alarm schemes to computerized logging systems. While full specification of such systems is beyond the scope of this standard, a general outline of one possible implementation is given in annex A.