RE: step-motor controller/driver connection

[zzt@ornl.gov (Jon Tischler)]

>Re controller <--> driver cabling
>
>
>% Mark Rivers suggests we avoid those dinky little screws usually found
>% on the floor near a nest of DB connectors.  There are two possibilities
>% that seem reasonable to me:
>
>1) get backshells with thumbscrews (e.g., Newark stock #93F8861)
>2) use spring latches (e.g., Newark stock #93F8863/93F8865)
>
>I'd prefer (2) with DB-9 connectors, since these latches can probably
>be attached (retrofitted, even) to anybody's cable and panel-mount DB
>connectors.  However, I'm not sure there's enough room to put eight
>spring-latched DB-25's on even a double-width VME transition board.
>
>> You can get spring clip latches for DB-connector shells. Also, make sure you
>> get shells with sturdy metal strain reliefs for cables. Not the shells
>>with the
>> flimsy plastic wedges or the one screw which is driven into the mantel
>>of the
>> cable from the side. Those don't work, they always rip out.

If those spring latches are the same kind of connector as used on the
standard ethernet transceiver cable, then I am against them.  They were
used for the trnasceiver cables for the same reason that are given here (no
more dinky screws, loosing dinky screws, ...).  However they are not very
strong, so that you loose reliability.  I even once heard someone say
something like 'I was the guy who first suggested that connector, and if I
had known how bad they are I would have gone with the regular screw kind.'

Jon Tischler



Jon Tischler                                        Solid State Division
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