Pathway MR Users Guide - Manual (Page 13)

DMXPathfinder LR Index
12
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.
T
EST
P
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.