Lenze EVS93xx CrossCutter - Manual (Page 253)

Cross Cutter
Appendix
 Prepared Solution Servo PLC / ECSxA 1.1 EN 6-85
6.6.3 TP_Window – Masking out mark pulses
If the setpoint distance (dnCycleLength_p) between two valid print marks is known, the
TP_Window function block can be used to mask out invalid print marks between two valid print
marks. For this purpose, a tolerance window dnTpWindowSize_p can be defined in which the
valid print-mark pulse must be located. Print-mark pulses are evaluated using the last-scan
value on a touch-probe-specific basis. Every time a new valid print-mark pulse is detected, the
centre of the tolerance window is adjusted in line with the print-mark pulse detected, in order to
prevent the mark pulse "running away". The assignment between the current print-mark pulse
and the tolerance window is deleted by setting control input bReset_b = TRUE. The next print-
mark pulse in the sequence defines the new tolerance window position and also serves as the
new home position for subsequent print-mark signals.
The function block has a comprehensive selection of status outputs:
• A valid print-mark pulse is output via output bTpReceivedOut_b and can be processed in
subsequent function blocks (e.g. the print-mark register, TP_Register function block). The
associated last-scan value corresponds to the value at input dnActIncLastScanIn_p.
• If the mask-out function has been activated for mark signals, the status of output bit
bTpWindowActive_b will change from FALSE to TRUE.
• Output bTpWindowOpen_b will be TRUE if the tolerance window is open: When
bTpWindowOpen_b = TRUE, a print-mark signal at input bTpReceivedIn_b will be switched
through to output bTpReceivedOut_b.
• If no print-mark pulses are detected at input bTpReceivedIn_b during the tolerance
window, when the print-mark window closes (bTpWindowOpen_b = TRUE => FALSE)
status output bNoTpInWindowDetected_b will be set to TRUE until the tolerance window
opens again (bTpWindowOpen_b = FALSE => TRUE).
• Output signal dnTpDistance_p outputs the distance between the last two valid mark signals
on a touch-probe-specific basis.