PRODUCER 3
06/18/97
Lighting Control Console
page
TEATRONICS LIGHTING CONTROLS,
TEATRONICS LIGHTING CONTROLS,
INC.
INC.
40
IN CASE OF TROUBLE
(continued)
SELF DIAGNOSTIC TECHNIQUES
(continued)
Another diagnostic technique which may prove useful is to patch all the dimmers to channel
zero then patch a suspected problem dimmer to channel one. Bringing up channel one then
should bring up only the suspect dimmer. By having only one dimmer in the patch it is easy to
see any flickering or jumping.
SORTING OUT THE AMX SIGNALS
The AMX-192 multiplex signal is a combination digital and analog control signal which cannot
be accurately measured without an oscilloscope. Some relative measurements can be attempted
with a meter which can tell the user which pin is which signal, assuming the console is operating
properly and the cable is not shorted.
AMX-192 uses three signals plus a COMMON. These signals are DATA, +CLOCK, and -
CLOCK. The first step to measuring the signal is to find the COMMON; this should be on pin
1 of the standard 4 pin connector but may be on pin 2 (CD-80 pinouts) or anywhere else if the
connectors are miswired. As a result of finding "COMMON" we will also find DATA which
should be on pin 3 but may be on pin 4 (CD-80).
To find "COMMON" and DATA:
1)
Place the console in blackout
2)
Set the meter to read approximately 5 volts DC full scale
3)
Measure the voltage between all pins
Voltage between pins 1 and 2 _________________________________
Voltage between pins 1 and 3 _________________________________
Voltage between pins 1 and 4 _________________________________
Voltage between pins 2 and 3 _________________________________
Voltage between pins 2 and 4 _________________________________
Voltage between pins 3 and 4 _________________________________
4)
Pick the pair of pins with the smallest voltage between them. Ignore the sign of
the voltage between pins for this comparison.
The lowest voltage is between pins _________ and _________
5)
Take the console out of blackout and take all dimmers to full. Be sure that the
dimmers are all patched to some channel at a level of full. Be sure that the grand
master is at full and that the crossfader makes the scene active. It is important
that the console be sending full levels to the dimmers.
