Pathway MR Users Guide - Manual (Page 14)

DMXPathfinder LR Index
13
The Fluke 650's signalling is not compatible with the DMXPathfinder MR
electronics or any other DMX generating or receiving equipment. Thus its
usage should be confined to the cable installation only.
Goddard Design Li'l DMX'ter -- This useful instrument can test most
aspects of the DMX Distribution System, from wiring continuity to signal
propagation through the DMXPathfinder electronics. Since the DMX'ter can
both generate and receive DMX512, it is 100% compatible with all aspects of
the distribution system, including any control system or receiving device. The
DMX'ter will directly control any receiving unit, and will verify the output of a
controller by displaying the data on an LCD readout. In addition, the instrument
will test cable continuity on all five XLR pins. Please refer to the Li'l DMX'ter
Operating Manual for more information.
Other Test Equipment -- The maintenance technician will find the
following additional test equipment useful:
.1 Oscilloscope -- for viewing data in conjunction with the
DMX'ter and its scope trigger module; for checking that both differential signals
are present on a given data line; for evaluating the performance of crosspoint
matrix and opto-repeater circuitry at higher operating speeds (greater than 250
Kbits per second).
.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 T 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