
13.MEASUREMENT B-63783EN-1/01
- 1396 -
Origin of the
coordinate
system
Skip signal input position
P
nc
P
Q
P
nc
: Current position within the CNC when the skip signal turns on (in mm
or inches)
P : Distance to be measured (in mm or inches)
Q : Servo delay (in mm or inches)
Using parameter SEB (bit 7 of No. 7300), the following calculation is
performed within the CNC:
P = P
nc
- Q
The distance to be measured, P, can be read with a macro variable.
Thus, the measurement error is only the dispersion that may occur
when the SKIP signal is sensed.
Signal
Skip Signal SKIP <X011#6> SKIP1<G000#3>
[Classification] Input signal
[Function] This signal terminates skip cutting. That is, the position where a skip
signal turns to "1" in a block containing G31 is stored in a custom
macro variable, and the move command of the block is terminated at
the same time.
[Operation] When a skip signal turns to "1", the control unit works as described
below.
- When a block contains a skip cutting command G31, the control
unit reads and stores the current position of the specified axis at
that time. The control unit stops the axis, then cancels the
remaining distance that the block was supposed to be moved.
NOTE
1 The skip signal width requires at least 10 msec.
2 The delay and dispersion of skip signal detection is 0
to 2 msec on the CNC alone, excluding those on the
PCM. Thus, the measurement error is equal to the
sum of 2 msec and the delay and dispersion of the
transfer of the skip signal on the PMC (including the
delay and dispersion of the receiver) multiplied by
the current feedrate.
3 After skip signal detection, the delay and dispersion
that may occur until feed is stopped is 0 to 8 msec.
To calculate the excess amount, the delay of
acceleration/deceleration, the delay in the servo,
and the delay in the PMC must be taken into
consideration.