Pathway MR Installers Guide User Manual

Page 13

DMXPathfinder LR Index

To replace an Output Module card, first remove the four front-panel Phillips

screws and the cover panel, then grasp the card stiffener bracket (or ejector
handles), and pull the card straight out of the module chassis. Carefully align
the replacement circuit board into the chassis' left and right card guides and
slide the unit in until it protrudes about 5mm, then push the module firmly into
its mating backplane receptacles. The card is not fully seated unless its front
edge is flush with the front of the metal chassis.

If the Crosspoint Card was replaced, check that the rotary switches have

been set the same as the replaced card. Test the system to ensure that the
fault has been corrected.

EST

ROCEDURES

System testing by maintenance personnel will usually be carried out in
response to a fault that has developed somewhere in the system. Powerful
diagnostic instruments are available to assist maintenance technicians with
this task: the Fluke Model 650 LAN Cable Meter, and Goddard Design Li'l
DMX'ter, amongst others. These will be described in more detail below. In
general, though, the troubleshooting instructions in this chapter are likely to
help solve the vast majority of problems encountered, especially where any
system downtime cannot be tolerated.

Tests using instrumentation will be performed where anomalies have

developed in the system that cannot be isolated with standard
troubleshooting procedures. Additionally, testing can establish minimum
network performance where non-DMX512 control equipment is to be
connected to the system.

Fluke 650 Cable Meter -- Please refer to the manufacturer's user's manual

for detailed instructions and theory before attempting to use this instrument.
It’s not obvious to the first time user! The Fluke 650 is provided with a
battery-powered remote plug-in unit, a set of 2 adapter cables (RJ45 to 5-pin
XLR) and an AC adapter. The unit may be powered by a 9-volt alkaline
battery, but battery life tends to be rather short with the 650 so use of the AC
adapter is recommended.

When the remote unit is connected to the other end of any DMX cable run,

the 650 will verify wiring continuity on all pins except ground (pin 1). Cable
length can also be measured with the instrument, and any anomalies, e.g.
changes in line impedance will be detected. The 650 measures performance
of the cable installation at up to 10 million bits per second.