Page 826 of 906 NTRB21 DTI/PRI/DCH TMDI card553-3001-211 Standard 3.00 August 2005To provide CEMUX communication with the card, changes are also requiredto create an I/O entry for the card.You can install this card in slots 1 through 4 in the MG 1000S. The card is notsupported in the MG 1000S Expansion. Up to four digital trunks aresupported in each MG 1000S.Note 1: For CISPR B group cabinets, the active Clock Controller(NTAK20) can only occupy slots 1-3. For FCC and/or CISPR A groupcabinets, this limitation does not exist - the Clock Controller can occupyany available slot 1-9.Note 2: On non-ECM system cabinets, the NTAK20 may be placed inslots 1-9. On cabinets NTAK11Dx and NTAK11Fx, the active NTAK20must be placed in slots 1-3 (slots 4-10 may not be used).Physical descriptionThe NTRB21 card uses a standard 9.5" by 12.5" multi-layer printed circuitboard with buried power and ground layers.The clock controllerdaughterboard is fastened by standoffs and connectors.The NTRB21 card has seven faceplate LEDs. The first five LEDs areassociated with the NTRB21 card. The remaining two LEDs are associatedwith the clock controller and DCHI daughterboards. See Figure 176.IMPORTANT!Each MG 1000S that has a digital trunk must have a clock controllerclocked to an external reference clock.
