The control algorithm during machining consists of a state
machine which reacts to the unpredictable occurrence of short
circuits during the machining. In normal operation, the values
of the signals “OCP” and “PSU ON” are checked to verify that
no problem has been encountered. If everything is fine (when
the PSU is pulsing and the OCP has not been triggered), the
controller reads the value of the current on one of the channels
of the data acquisition board and computes the appropriate
step size necessary to maintain the interelectrode gap to a
constant value. Controller constantly loops into that step unless
an over current protection signal is triggered or the PSU
stops pulsing. If the PSU stops pulsing, the controller interrupts
the programme and display an error message on the
HMI.