Nortel Circuit Card, Installation Manual, Page: 685 / 908

NT8D41BA Quad Serial Data Interface Paddle Board Page 685 of 906
Circuit Card Description and Installation
The QSDI paddle board is normally installed into a socket in the network area
of the backplane. This allows it to be accessed by either of the system
processors. This is necessary because the active CPU switches automatically
each night at midnight and whenever a fault occurs on the active CPU card.
The QSDI paddle board can also be installed into a socket in the CPU area of
the backplane (supported in NT6D39AA shelves only). This is done when
performing maintenance or an upgrade on the system.
The QSDI paddle board is plugged into the CPU that is not the active system
CPU. One of the serial ports on the QSDI paddle board is then connected to
a maintenance terminal and the CPU board is put into maintenance mode.
Diagnostics can then be run from the maintenance terminal without having to
stop the system. This is also used to perform a parallel reload of the system
software without affecting the operation of the switch.
Connector pin assignments
The RS-232-C signals for port 1 through port 4 are brought out on connector
J1 through J4 respectively. The pinouts for each port are identical to those for
each of the other three ports. Table 215 shows the pin assignment that applies
to each connector.
Table 215
Connectors J1, J2, J3, and J4 pin assignments
Pin # Signal Purpose in DTE mode Purpose in DCE mode
1 DCD Data Carrier detect (Note 1) Data Carrier detect (Not used)
2 RD Transmitted data Received data
3 TD Received data Transmitted data
4 DTR Data terminal ready Data terminal ready (Note 2)
5 GND Signal Ground Signal Ground
6 DSR Data set ready (Note 1) Data set ready
7 RTS Request to send (Not Used) Request to send (Note 2)