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Electronic Theatre Controls Inc

Dimmer Order Incorrect After Upgrading Sensor Classic Touring and Delta 1 Racks


In CEM Classic the processor could only handle splitting up the phase bars more than six ways.  This was a problem for 36/72, 48/96 large frame and 48/96 Small double touring racks as well as Delta 1 48/96 racks. To resolve this we manually split up the phasing using a PCB that lands all 4 outputs, did a hard patch, and passed the signal on to the bump button boards (if added) and then to signal distribution cards.  We call this the spider board  (7050B5014 SNSR 96X SPIDER CARD ASSY). However, if the spider board is still installed after upgrading one of these rack types from Classic to Plus or 3, the phase splitting will be done by both the board and the new processor, causing an incorrect dimmer order.

Since the new CEM + & CEM3 processor have enough processing power to do all the phasing internally you will need a 7150B5618 CEM+ Non-spider LF Circuit Board Assembly to take out the hard patch that is put in place by the Spider Board. With the thicker back planes of the CEM+ and CEM3, using three HW9454  8-32 stand offs help provide enough room to get the backplane to fit.

A Sensor Touring Spider Board


  1.  We have added a 7150B5618 CEM+ Nonspider LF Circuit Board Assembly to the upgrade kit starting in December of 2018.
  2. We have added three HW9454 8-32 Standoffs to the upgrade kit starting in December of 2018.

If you have a kit manufactured before December of 2018 and need these parts for upgrading a Delta rack to CEM+ or a Classic Touring Rack to CEM3, please contact ETC Technical Services.


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