Nortel Networks 553-3001-211 manual MMI connections

NT5D11 and NT5D14 Lineside T1 Interface cards Page 207 of 894

One of the ways it can report information is through this external alarm connection. If connected, the lineside T1 card’s microprocessor activates the external alarm hardware if it detects certain T1 link problems that it has classified as alarm levels 1 or 2. See “Man-Machine T1 maintenance interface software” on page 213 for a detailed description of alarm levels and configuration. If an alarm level 1 or 2 is detected by MMI, the lineside T1 card will close the contact that is normally open, and will open the contact that is normally closed. The MMI command Clear Alarm will return the alarm contacts to their normal state.

MMI connections

P5 connector pins 2, 3, 5, 7 and 9 are used to connect the lineside T1 card to the MMI terminal and daisy chain lineside T1 cards together for access to a shared MMI terminal. When logging into a lineside T1 card, “control 2” is asserted by that card, which informs all of the other cards not to talk on the bus, but rather to pass the data straight through. The pins labeled “control 1” are reserved for future use. As with the external alarm connections, MMI connections are optional. Up to 128 lineside T1 cards, located in up to 16 separate IPE shelves, can be linked to one MMI terminal using the daisy chaining approach.

If only one lineside T1 card is being installed, cable from the DB9 female connector labeled “P5” (towards MMI terminal) to one of the COM ports on the back of any TTY, a PC running a terminal emulation program, or a modem. For installations of only one card, no connection is made to the DB9 male connector labeled “P4” (away from MMI terminal).

If two or more lineside T1 cards are being installed into the system, the MMI port connections can be daisy-chained together so that only one MMI terminal is required for up to 128 lineside T1 cards. See Figure 30 on page 209. Cards can be located in up to 16 separate IPE shelves. Any card slot in the IPE shelf can be connected to any other card slot; the card slots connected together do not need to be consecutive.

Circuit Card Description and Installation