N4: Own channel - only 840D sl9.2 Stroke controlExtended FunctionsFunction Manual, 03/2013, 6FC5397-1BP40-3BA1 557The chronological sequence of events for punching and nibbling is controlled by the twosignals A0 and E0:A0 Set by the NCK and identical to stroke initiation.E0 Defines the status of the punching unit and identical to the "Stroke active" signal.The signal states characterize and define times t 1 to t4 in the following way:t 1 The motion of the workpiece (metal sheet) in relation to the punch is completed at instant t 1 .Depending on the criterion defined for stroke initiation (see Section "Criteria for stroke initiation(Page 558)"), the high-speed output A 0 is set for punch initiation ①.t 2 The punching unit signals a punch movement via high-speed input E0 at instant t2 .This is triggered by signal A 0 ②.For safety reasons, signal E 0 is high-active (in the case of an open circuit, "Stroke active" isalways set and the axes do not move).The "Stroke active" signal is not reset again until the tool has moved away from the metalsheet (t 4 ).t 3 The NC reacts to the "Stroke active" signal at instant t 3 by canceling the "Stroke initiation"signal ③. From this point in time onwards, the NC is in a waiting state. It simply waits forcancellation of the "Stroke active" signal so it can initiate the next axis motion.The next stroke can be initiated only after signal A 0 has disappeared.t 4 The punching operation is complete at instant t 4 , i.e. the punch has exited from the metal sheetagain.The NC reacts to a signal transition in signal E 0 by starting an axis motion ④.The reaction of the NC to a signal edge change ④ is described in the section headed "Axisstart after punching".NoteThe stroke time is determined by the period Δt h = t4 - t1.Reaction times at instant t 4 between the signal transition of E0 and the start of the axismotion must also be added.