Definity TN763D Auxiliary 4 Trunk Circuit Card

Provides 4 ports. Each Port has T, R, SZ1, S, and S1 signal leads. Used for on-premises applications such as music-on-hold, loudspeaker paging, code calling, and recorded telephone dictation access. Trunk uses loop-start on tip and ring 1-way in, 1-way out, or 2-way 2-wire transmission. Two addition supervision and/or make busy information.