Nortel Networks 553-3001-211 manual Serial Data Interface SDI cards, NT8D41BA

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Serial Data Interface (SDI) cards

The NT8D41BA QSDI paddle board provides four bidirectional asynchronous serial ports for the system processor, and the QPC841 QSDI card also provides four. Any device that conforms to the RS-232-C serial communication standard can be connected to these serial ports.

The QPC513 ESDI card provides two fully synchronous serial ports for the system processor. The ESDI card communicates using the Link Access Procedure Balanced (LAP-B) synchronous communication protocol.

The electrical interface uses either standard RS-232-C signals or a special high-speed interface that combines the high-speed differential interface of the RS-422-A standard with the handshake signals of the RS-232-C standard.

The RS-232-C interface is normally used when data rates are less than 19.2 Kbps, and the cable length is less than 15.24 m (50 ft). The high-speed interface is used when the signal rates are greater than 19.2 kbps (up to 64 kbps) and/or when the cable length is greater than 15.24 m (50 ft).

Table 8 shows compatibility between the three SDI cards and the various switch options.

Table 8

Serial data interface cards

			Compatible System Options
Card	Ports	Port types	51C, 61C	81C
NT8D41BA	4	RS-232-C asynchronous	X	X
QPC841	4	RS-232-C asynchronous	X	X
QPC513	2	RS-232-C synchronous or	X	X
		high-speed synchronous*

*See the section on the QPC513 card in this manual for details on the high-speed interface

The NT8D41BA QSDI paddle board does not have a front panel. It mounts to the rear of the backplane in the NT5D21 Core/Network module, and does

553-3001-211 Standard 2.00 September 2004