Mechanical Restraints; Scsi Device Grounds; Figure 8: Example Scsi Cable - Performance Computer PT-VME161 User Manual

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Section GETTING STARTED
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Mechanical restraints

Depending upon your mechanical configuration, tie wraps or cable clamps may be necessary to
provide mechanical support for the cable. Most VME backplanes and SCSI devices do not provide
locking mechanisms or other means of mechanically securing the connectors. They depend on the
insertion force of 50+ pin and socket connections to hold the attached connector and cable in place.
Nothing is more frustrating than intermittent errors due to a connector that has been pulled out by
the weight of its own cable.
PTI recommends that, if possible, you attach the cable to some nearby metal work with tie wraps or
cable clamps to provide mechanical support for the cable, especially if it is long (more than 18 inches
between device connections) or if it is in a high vibration environment.

SCSI device grounds

Most SCSI device vendors provide a method for connecting their device to chassis ground. It is
suggested that you follow the vendor's recommendations for its use. Proper use of these connections
generally improves the overall noise margins of a system.
24 Extensible Single Board Computer/Controller User's Manual
AMP 1-746288-0 (connector)
AMP 499252-4 (strain relief)

Figure 8: Example SCSI Cable

6 Meter Maximum
Pin 1 Indicator
50 Conductor Ribbon Cable
64 Pin VMEbus "P2" Connector
1
50 Pin Flat Cable Connectors
for SCSI devices (up to 7)
1