... optionally4 gates for each channel, A and B for alarm gates, G for tracing gate and W for ... each channel, A and B gates are alarm gates, G is a tracing gate and W is a self-locking ... gateAlarm IndicationLED indication for A, B and G gates in ... each channel. LED indication and audible alarm for A, B, G and W gatesDelay Alarmdivided into two ways , delay ...