Update on the laser probe. Thanks to some input from this group and a discussion with Peter at Mesa tech, I now have a laser distance measuring device reading to within 0.001”. The range of my instrument is about 2” and I need only about 1/2”, so I can get the precision down to 1/4 of that. Not that I need it.
As I mentioned earlier, the laser instrument is a Keyence iA-1000/iA-060. The output from this device is a scalable analog 0.5-4V signal. I built a small board that powers the laser, converts the voltage to a frequency, and feeds signal into an encoder configured for count mode. 24v Power enters the board via a pair of screw terminals. This power is filtered, regulated, then brought out to the laser. The analog voltage signal is converted to a frequency signal, which then goes through an isolator and is delivered to the mesa board via the P1 expansion socket I used an Analog Devices AD7741 voltage to frequency converter. This device needs to be clocked with either a clock input or a crystal. I used a step generator output for this. The isolator I used is a NVE IL-712-2E. This is a 2-channel “digital isolator” with channels running in opposite directions. This device is remarkably fast; propagation delay is 15ns and max pulse width distortion is 3ns. I have never before heard of digital isolators. Are they a new thing? Any reason why not to use them over optical isolators? If I had been smart, I would have just purchased a mesa THCAD card. I would have accomplished more but learned less. Thaddeus Waldner _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
