Browse Prior Art Database

Active Wrap Plug without Power Source

IP.com Disclosure Number: IPCOM000108958D
Original Publication Date: 1992-Jul-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 3 page(s) / 116K

Publishing Venue

IBM

Related People

Beavers, JA: AUTHOR [+3]

Abstract

There is an emerging 52-Mbit/sec interface called High-Speed Serial Interface or HSSI. This interface is used as an interface between a 3172 Model 2 internet controller and a vendor-supplied telecommunications resource manager. One of the reliability, accessibility and serviceability (RAS) requirements is a "wrap plug" which, when attached to the adapter card, returns any transmitted data back to the adapter card under test. This type of wrap test is used by manufacturing and field personnel to verify the card is fully functional and capable of both transmitting and receiving data before the card is attached to any cables or vendor boxes.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Active Wrap Plug without Power Source

       There is an emerging 52-Mbit/sec interface called
High-Speed Serial Interface or HSSI.  This interface is used as an
interface between a 3172 Model 2 internet controller and a
vendor-supplied telecommunications resource manager.  One of the
reliability, accessibility and serviceability (RAS) requirements is a
"wrap plug" which, when attached to the adapter card, returns any
transmitted data back to the adapter card under test.  This type of
wrap test is used by manufacturing and field personnel to verify the
card is fully functional and capable of both transmitting and
receiving data before the card is attached to any cables or vendor
boxes.  The HSSI adapter card is a "timing slave" to the HSSI
interface, which means it must place data on the interface
synchronous to an external clock which is usually supplied by the
resource manager.  During the wrap test, there will be no resource
manager to supply the needed clock; therefore, the wrap plug must be
able to generate the needed clock.

      The two traditional methods of supplying an external clock on a
wrap plug use either a battery or draw voltage from card-under-test
to supply power for a crystal oscillator.  Both of these solutions
have inherent problems.  The battery requires an indicator to inform
the user when the battery has run out, requires field personnel to
carry spare batteries, and presents an environmental problem of
disposing spent batteries.  Drawing power from the card-under-test is
a safety hazard issue because the power must be brought out on the
pins of a connector, which leads to the possibility of shorting the
card power.  This invention draws power from control signals coming
from the HSSI adapter card which are at ECL logic levels.  The
advantage of drawing power this way is isolation from the raw power
supply, no batteries running out, and simplifying the use and
operation of the wrap plug.  This invention also allows construction
of a very small wrap plug which simply plugs on to the
card-under-test.  With a self-contained, no-battery test tool, field
personnel do not have to connect several boxes up to perform the
test, and only have to carry one small connector-sized device...