This is maybe a strange question, but I'm wanting to write a macro to add to a screen that will allow me to make repeated measurements on the probed position on executing a G31 - basically I am interested in the variance of the sensed position, or how accurate the probe is. This is partly to evaluate probes, but more because what I'm actually wanting to do is evaluate the precision of photointerrupters sensing a vane. At the moment my Mach 3 is set up to trigger on a negative going (i.e. grounded) signal when the probe touches which is fine for the photointerrupter when looking at one edge, but they also display hysteresis so I'd also like to look at the other sense, when the vane moves out of the gap and the signal goes positive. What I'd really like to do is change the sensing polarity of the digitise signal from within the macro. Can anyone advise if this is possible please?
John.