Nortel Passport 7400, Установка оборудования, техническое обслуживание и устранение неисправностей, Страница: 303 / 438

Chapter 37 Hardware procedures 303
Passport 7400 Hardware Installation, Maintenance, and Upgrade 5.2S1
Making customer equipment cables
Make customer equipment cables following this general procedure.
Prerequisites
• Ensure that you know the appropriate cable specifications, including
assembly parts, pinouts and standards to which a cable must comply. For
more information, see 241-7401-200 Passport 7400 Hardware
Description.
• Ensure you have assembled all required cable parts.
Procedure steps
1 Assemble the cable according to the specifications in 241-7401-200
Passport 7400 Hardware Description
and your company operational
procedures.
2 If you are making a shielded cable, make a braided shield. See the
procedure “Making a braided shield” (page 300).
3 Ground the cable according to site practices.
To avoid EMI problems, terminate shield grounds on equipment at the
Passport end as well as the customer end. This assumes the Passport
equipment and the customer equipment are properly grounded to avoid
any ground loop problems.
If necessary in order to avoid ground loops, you can terminate the shield
ground at one end only.
4 Test end-to-end connections with an ohmmeter set to the lowest
resistance range. Ensure that each connection is correct. Also ensure
that the connector pins are not shorted together or to the connector
shield.
CAUTION
Risk of compromise to EMI rating
The shielded cables that you assemble must have a
braided shield. See the procedure, “Making a braided
shield” (page 300) Failure to properly construct
interface cable assemblies can compromise the EMI
rating and affect the product compliances.