NTRB21 DTI/PRI/DCH TMDI card Page 837 of 906Circuit Card Description and InstallationConnector pinoutThe connection to the external digital carrier is through a 15 position MaleD-type connector.NTAK20 Clock Controller (CC) daughterboardDigital Trunking requires synchronized clocking so that a shift in one clocksource results in an equivalent shift of the same size and direction in all partsof the network.The NTAK20 clock controller circuitry synchronizes the CS 1000S,CS 1000M Cabinet, and Meridian 1 PBX 11C Cabinet to an externalreference clock and generates and distributes the clock to the system. TheCS 1000S, CS 1000M Cabinet, and Meridian 1 PBX 11C Cabinet canfunction either as a slave to an external clock or as a clocking master to thenetwork.The NTAK20AD and NTAK20AA versions of the clock controller meetAT&T Stratum 3 and Bell Canada Node Category D specifications. TheNTAK20BD and NTAK20BA versions meet CCITT stratum 4specifications. See “NTAK20 Clock Controller daughterboard” on page 735.Table 265DS-1 line interface pinout for NTBK04 cableFrom 50-pinMDF connector To DB-15 Signal name Descriptionpin 48 pin 1 T transmit tip tonetworkpin 23 pin 9 R transmit ring tonetworkpin 25 pin 2 FGND frame groundpin 49 pin 3 T1 receive tip fromnetworkpin 24 pin 11 R1 receive ring fromnetwork
