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Electronic Theatre Controls Inc

Swapping out a CEM3 Processor



If a CEM3 fails, you may need to swap in a spare processor to continue operating.

Alternatively, if a CEM3 appears to fail or malfunction, you may need to swap in a processor from another rack to see if the problem lies with the processor or elsewhere.

The rack configuration is stored on both the processor and the backplane memory chip. This means that if a processor fails and needs to be replaced, you can reload the configuration from the backplane, and be up and running again quite fast.


It is a good idea to create backup copies of your configuration - this can be on a USB stick, or in a Concert file which contains all your racks



Always power down your rack before inserting or removing a CEM3!

Scenario 1: Using a factory default processor

Example: you have one or more Sensor racks and keep an unused spare processor in a box

  1. Power down your rack
  2. Insert the spare processor
  3. Power up the rack
  4. The processor will automatically take the config from the backplane, and continue to operate as before


Scenario 2: Using a processor with an existing config

Example: you have a fauly processor, and want to use a processor from another performance space as a spare

  1. Create a backup copy of the config in the "donor" processor, just in case
  2. Power down your racks
  3. Remove the old processor, and insert the new processor into the suspect rack
  4. Power up the suspect rack
  5. You will be presented with a message reading "The configuration in this CEM3 does not match the rack. Switching to the rack config in X seconds". Allow the countdown to finish, or choose "Use Rack Config"
  6. The configuration will be loaded from the backplane into the processor

If the above actions show that the processor is ok, contact ETC technical services in your region for further advice

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