... Straightforward signaling Audio frequency testing Loop circuit delay testing Automatic protection switching time testing (APS) Voice monitoring Signal ... 826/M. 2100 error analysis Multi error and alarm inserting Three input modes (terminating, bridging and monitoring) Two ... V.28, V.35, V.36, X.21, RS-449, RS-485, RS422, EIA-530, EIA-530A datacom testing ... %~90%, non-condensing SAT-1CS E1 Datacom Tester