Also available in the 4-wire mode is selectable normal or reversed simplex signaling. In both 2-wire and 4-wire interfaces,provisionable wide-range gain/attenuation settings are provided. For ETO mode, both sourcing or sinking sealing current options are available when sealing current is required. The SS 2/4 card is not software upgradeable.
For all signaling modes, the Tellabs 1000 MSAP SS 2/4 plug-in card supports full equalization for 2-wire interfaces and built-in precision balancing with each equalization setting for echo cancellation over any loop. For 4-wire interfaces, post-equalization (transmit direction only) is provided. These equalization settings are available via provisionable selections for different cable configurations. Passive mismatch equalization is also available in the 4-wire mode, via selectable 150 ohm/600 ohm settings, for both transmit and receive directions.