My machine(Cadet Mate VMC) throws this alarm as soon as the cycle start button is pressed. I have ensured the machine is fitted with DNC-B option. I've been able to punch and read whole programs in and out through CN0. However, when I move that cable to the DNC port and flip the buffer on, cycle the power, both LEDs light up over the communication switches. I turn on the control and go to Auto. Then I hit cycle start and immediately get the 3218 alarm. I've configured my CMPS settings per Okuma's documents sent by my local rep and it matches my book. I also replaced the CCP board(DNC board) at the recommendation of my local rep. I'm still getting the same alarm and have gained to ground on this issue in several weeks, despite putting MANY man hours into it. Any help would be greatly appreciated!