Description
The SIGA-IB is a Signature Series detector base with a built-in line fault isolator for use on a Class A signaling line circuit (SLC). It does not operate without a detector and does not support the SIGA-LED.
The isolator operates as follows: A short on the line causes all isolators to open within 23 ms; at 10 ms intervals, beginning on the side of the Class A circuit nearest the loop controller, the isolators close to provide the next isolator down the line with power; when the isolator next to the short closes, it reopens within 10 ms. The process repeats beginning on the other side of the loop controller.