Dmx512 Connection; Troubleshooting - ACME MH-6616S User Manual

5.4 DMX512 Connection

The DMX512 is widely used in intelligent lighting control, with a maximum of 512 channels.
1. If you use a controller with 5 pins DMX connector, you need to use a 5 to 3 pin adapter.
2. At last unit, the DMX cable has to be terminated with a terminator. Solder a 120-ohm
1/4W resistor between pin 2(DMX-) and pin 3(DMX+) into a 3-pin XLR-plug and plug it in
the DMX-output of the last unit.
3. Connect the unit together in a "daisy chain" by XLR plug from the output of the unit to the
input of the next unit. The cable can not branched or split to a "Y" cable. DMX512 is a
very high-speed signal. Inadequate or damaged cables, soldered joints or corroded
connectors can easily distort the signal and shut down the system.
4. The DMX output and input connectors are pass-through to maintain the DMX circuit,
when power is disconnected to the unit.
5. Each lighting unit needs to have an address set to receive the data sent by the controller.
The address number is between 0-511 (usually 0 & 1 are equal to 1).
6. The end of the DMX512 system should be terminated to reduce signal errors.
7. 3 pin XLR connectors are more popular than 5 pins XLR.
3 pin XLR: Pin 1: GND, Pin 2: Negative signal (-), Pin 3: Positive signal (+)
5 pin XLR: Pin 1: GND, Pin 2: Negative signal (-), Pin 3: Positive signal (+)
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6. Troubleshooting

Following are a few common problems that may occur during operation. Here are
some suggestions for easy troubleshooting:
A. The unit does not work, no light and the fan does not work
1. Check the connection of power and main fuse.
2. Measure the mains voltage on the main connector.
3. Check the power on LED.
B. Not responding to DMX controller
1. DMX LED should be on. If not, check DMX connectors, cables to see if link properly.
2. If the DMX LED is on and no response to the channel, check the address settings and
DMX polarity.
3. If you have intermittent DMX signal problems, check the pins on connectors or on PCB
of the unit or the previous one.
4. Try to use another DMX controller.
5. Check if the DMX cables run near or run alongside to high voltage cables that may
cause damage or interference to DMX interface circuit.
C. Some units don't respond to the easy controller
1. You may have a break in the DMX cabling. Check the LED for the response of the
master/ slave mode signal.
2. Wrong DMX address in the unit. Set the proper address.
D. No response to the sound
1. Make sure the unit does not receive DMX signal.
2. Check microphone to see if it is good by tapping the microphone
E. One of the channels is not working well
1. The stepper motor might be damaged or the cable connected to the PCB is broken.
2. The motor's drive IC on the PCB might be out of condition.
F. The lamp is cutting out intermittently
1. The lamp is not working well. Check the main voltage either too high or too low.
2. Internal temperature may be too high. Check and if necessary replace the fan on the
head.
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