Page 302 of 894 NT5D60/80 CLASS Modem card (XCMC)

The CLASS modem card circuitry is mounted on a 31.75 cm by 25.40 cm (12.5 in. by 10 in.) double-sided printed circuit board. The card connects to the backplane through a 160-pin edge connector.

The faceplate of the CLASS modem card is equipped with a red LED that lights when the card is disabled. When the card is installed, the LED remains lit for two to five seconds as a self-test runs. If the self-test completes successfully, the LED flashes three times and remains lit until the card is configured and enabled in software, then the LED goes out. If the LED continually flashes or remains weakly lit, replace the card.

Functional description

The CLASS Modem card is designed to plug into any one of the peripheral card slots of the IPE module. The CLASS modem card supports up to 32 transmit-only modem resources, using a DS30X interface. Up to 255 modems can be configured per system.

The CND transmission process begins with the CS 1000 Release 4.0 software sending an initiating message to the CLASS Modem card indicating the length of the CND information and the type of the CND information flow to be transmitted. In response, the CLASS Modem card assigns a message buffer to capture the CND information from the CS 1000 Release 4.0 software.

System software then sends the CND information to the CLASS Modem card, one byte at a time, where it is stored in the message buffer. If the CLASS Modem card receives more bytes than were specified in the initiating message, then the additional bytes will be discarded and will not be included in the CND memory buffer.

Once all of the CND information has been stored in the memory buffer, the CLASS Modem card begins transmission when requested by the system software. Data is sent one ASCII character at a time. The CLASS Modem card inserts a start and stop bit to each ASCII character sent.

The transmission of the calling party name/number to the terminating telephone is accomplished through asynchronous FSK simplex-mode transmission at 1200 bits/second over a 2-wire loop, in accordance with the

553-3001-211 Standard 2.00 September 2004

Page 302
Image 302
Nortel Networks 553-3001-211 manual 302 of 894 NT5D60/80 Class Modem card Xcmc