Pathway LR Installers Guide - Manual (Page 16)

DMXPathfinder LR Maintenance & Testing
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.2 Frequency Generator -- for testing crosspoint matrix and
opto-repeater high-speed performance. Useful for evaluating whether other
systems with higher data rates can be used in the network.
.3 Digital Volt/Ohm Meter -- a general purpose tool for
checking continuity, termination resistor values and power supplies.
A
DVANCED
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ROUBLESHOOTING
As described earlier, basic troubleshooting usually involves isolating a
troublesome or defective opto-repeater circuit, card or module and replacing it
with a known good one. It may also include checking for obvious things such as
incorrect addressing or DMX protocol incompatibility with DMX receiving
devices, absence of a line terminator, defective DMX patch cables, or even
incorrect control console configuration.
Once all basic troubleshooting checks have been completed, without the
desired resolution of the problem, more sophisticated faultfinding may be
carried out. It is recommended to use a portable computer connected to the
RS232 PC-COM port on one of the Output Modules so that test patching and
diagnostics can be done right at the DMXPathfinder itself. First, however, try
swapping input or output cable connections on the back of the Pathfinder
modules with adjacent ones to use a different receiver and transmitter circuits.
Next, a DMX tester should be used to either transmit DMX in place of the control
console, or receive DMX in place of the receiving device(s). Check the
receiving device by connecting the DMX tester directly to it in transmit mode.
Then set the tester to receive mode and monitor the data coming to the
Pathfinder from the console, by plugging into the Input Module faceplate XLR
with a female-female cable. If this test does not point to the data source or the
receiving device as being the cause of the problem, there may be a slight
incompatibility between them as far as DMX512 is concerned. However, if the
two units had previously worked together, these tests will point to a problem in
the DMX cable installation or in one of the DMXPathfinder modules.
At this point, the suspect Output Module’s output card or should be
withdrawn from its chassis and the spare unit inserted in its place (remember to
power down before withdrawing or inserting any cards). If this proves that the
original unit is defective, inspect the card for signs of damage or any other
obvious cause. Return the defective card to the factory for repair unless you
have the facilities to carry out your own service. For more serious defects, such
as power supply or fan failure, disconnect the entire module and take it to the
test bench for repair, or return it to the factory. DMXPathfinder LR modules are
not difficult to service with basic tools and test equipment. If the suspect module