Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Automatic Self-Test Handled by a Data Terminal Equipment Wrap Plug

IP.com Disclosure Number: IPCOM000035712D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Maiffredi, B: AUTHOR [+2]

Abstract

A double-sided wrap plug is used to test the DTE interface side of an integrated modem. It is connected to the special cable which connects the DTE to the modem. When it is installed the modem performs an automatic self-test using the Telco wrap plug (which should be plug first).

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 62% of the total text.

Page 1 of 1

Automatic Self-Test Handled by a Data Terminal Equipment Wrap Plug

A double-sided wrap plug is used to test the DTE interface side of an integrated modem. It is connected to the special cable which connects the DTE to the modem. When it is installed the modem performs an automatic self-test using the Telco wrap plug (which should be plug first).

This process represents a facility to test an integrated PS/2 modem. Indeed, it is not necessary to run a PS/2 application in order to send a self-test command through the DTE interface or open the PS/2 cover to see if the LED (light-emitting diode) indicator of the integrated modem card is OK. Moreover, the DTE interface modem is tested.

The wrap plug is double-sided because the number of EIA drivers is greater than the number of EIA receivers (7 drivers, 4 receivers). Data Terminal Ready lead and Data Set Ready lead of the DTE interface are wrapped together on both side, and an LED is connected between the Data terminal ready driver output and ground through a resistor to limit the current and a diode to limit the reverse voltage on the LED. A 'wrap plug present' line is connected to ground on both sides of the wrap plug.

Wrap side A wiring: Clear to send wrapped on Request to send Data set ready wrapped on Data terminal ready Data carrier detect wrapped on Data signal rate select Transmit data wrapped on Receive data Wrap side B wiring: Ring indicator wrapped on Ready to send Data terminal ready wrapped on Transmit clo...