Product description
2.5 Probe damped signal (PDAMP)
During high-speed position moves (fast traverse), it is necessary to reduce probe
sensitivity to prevent vibration causing unwanted triggers. The CMM controller must
assert the PDAMP signal on the PICS port, to switch the PI 200 into the low sensitivity
mode known as ‘probe damped’. In this mode, deflection of the stylus will generate
SYNC and HALT simultaneously, but only if the probe signal remains above the
damped trigger level for longer than the time delay selected by switches 11 and 12 as
indicated in figure 5.
NOTE:
The probe cannot take accurate points when damped mode is active, and the
CMM controller must clear the PDAMP signal to return the probe to normal sensitivity
before taking a gauge point. It is important that PDAMP is only cleared when vibrations
of the CMM and probe stylus have reduced to a sufficiently low level to avoid spurious
re-triggering at the end of the position move.
Probe damped mode is indicated by an LED on the PI 200 front panel.
Trigger level 2
Probe signal
V
t
Delay time set by
switch 11 and switch 12
SYNC
HALT
Trigger level 1
Probe damped
level
Figure 5 -
SYNC and HALT signal timing for a trigger in damped mode
