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December 1999
3611-A2-GZ43-30
4. Attach the four metal standoff posts to the DSU with the four Phillips-head screws and flat washers.
Tighten the screws until the standoff posts fit snugly against the circuit card. Do not overtighten.
5. Install the black-banded end of the double-ended pin header into its mating connector on the DSU. Make
sure that the double-ended pin header is full seated.
6. On a flat work surface, orient the DSU to its upright position, with the faceplate over the edge of the table
(so the latches hang over) and pointing toward you (just as it would sit in the carrier). Orient the modular
TDM (or modular MCMP) circuit card in the same manner, to the immediate right of the modular DSU
circuit card.
Keeping the modular circuit cards (that is, the modular TDM and modular DSU, or the modular MCMP
and modular DSU) perpendicular to the work surface, move the modular circuit cards closer to one
another, ensuring that their bottom edges are flat against the work surface. Look between the circuit cards
to guide the double-ended pin header into its mating connector on the modular TDM (or modular MCMP)
and at the same time, ensure that the snaplock posts are aligned with their mating holes in the modular
TDM (or modular MCMP). Make sure that the double-ended pin header is properly aligned. Then, snap
the snaplock posts into the modular TDM (or modular MCMP).
7. Use the remaining four Phillips-head screws and flat washers to secure the standoff posts to the modular
TDM (or modular MCMP).
8. At the front of the carrier, make sure that both the top and bottom edges of the modular DSU and modular
TDM (or modular DSU and modular MCMP) circuit cards are correctly aligned in their respective circuit
card guides. Then, slide the modular DSU-TDM unit into the carrier and press the faceplate latches on
both the modular DSU-TDM (or modular DSU-MCMP) circuit cards to secure the circuit cards to the
connector module.
9. Rotate the circuit pack lock on the modular DSU circuit card faceplate back into the closed position and
tighten the screw (Figure 2).
10. Return to the rear of the carrier and tighten the screws on the connector module.
11. Connect the DTE interface cables (Figure 3). Install ferrite chokes, if provided, as close to the cable
connector as possible.
When power is applied to the modular circuit cards, the modular DSU performs a self-test routine. The
modular DSU determines what options (DBM, MUX–TDM or MCMP) are installed. It then initiates a
Device Test on itself and each of the available options. During the tests, all indicators on the modular
DSU’s faceplate light briefly.
