Nortel Networks Circuit Card User Manual

 NT6D80 MSDL card

Emulation mode Each port can be configured to emulate a DCE port or a 
DTE port by setting the appropriate switches on the MSDL. For details on 
how to set the switches, refer to “Installation” on 

 of this document.

DCE is a master or controlling device that is usually the source of information 
to the DTE and may provide the clock in a synchronous transmission linking 
a DCE to a DTE.

DTE is a peripheral or terminal device that can transmit and receive 
information to and from a DCE and normally provides a user interface to the 
system or to a DCE device.

Interface Each MSDL port can be configured as an RS-232 or an RS-422 
interface by setting the appropriate switches on the card.

Table 150 lists the RS-232 interface specifications for EIA and CCITT 
standard circuits. It shows the connector pin number, the associated signal 
name, and the supported circuit type. It also indicates whether the signal 
originates at the DTE or the DCE device.

This interface uses a 26-pin (SCSI II) female connector for both RS-232 and 
RS-422 circuits.

RS-422

Switches 

Mode

DTE or DCE

Switches 

1

Frame Ground (FG)

AA

102

—

—

2

Transmit Data (TX)

BA

103

X