Dmx 512 Connection; Troubleshooting - ACME CHEETAH LED-GF50 User Manual

7. DMX 512 Connection

The DMX 512 is widely used in intelligent lightings and with a maximum of 512 channels.
1. If you using a controller with 5 pins DMX output, you need to use a 5 to 3 pin
adapter-cable.
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 be branched or split to a 'Y'
cable. DMX 512 is a very high-speed signal. Inadequate or damaged cables,
solder 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 connected 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 0-512 (usually 0 & 1 are equal to 1).
6. The end of the DMX 512 system should be terminated to reduce signal errors.
7. 3 pin XLR connectors are more popular than 5 pin XLR.
3 pin XLR: Pin 1: GND, Pin 2: Negative signal (-), Pin 3: Positive signal (+)
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5 pin XLR: Pin 1: GND, Pin 2: Negative signal (-), Pin 3: Positive signal (+)
Pin 4/5: Not used.

8. Troubleshooting

Following are a few common problems that may occur during operation. Here are some
suggestions for easy troubleshooting:
A. The fixture does not work, no light
1. Check the connection of power and main fuse.
2. Measure the mains voltage on the main connector.
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 fixture 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 fixtures don't respond to the easy controller
1. Check the LED for the response of the master/ slave mode signal.
2. Check if the unit is receiving DMX signal and cut it off.
D. No response to the sound
1. Make sure the fixture 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.
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