Background
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These ATCs use an ATC control board (powered through the 68 Vdv DC-BUS) and power drawbar control board (powered through a 12 Vdc daughter board via the DC-BUS). These two communicate by an RJ11 cable (DB3). Finally, the power drawbar control board has an additional RJ11 (DB1) that is connected to the VFD so they can commutate whether the spindle is running or not.
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