With Mach 4 and the SmartBOB-USB, I see the spindle input toggling in both the Mach 4 diagnostic and the SmartBOB real time port display when I run the spindle but there is no RPM display in Mach. I suspect I'm missing some set up step. Also, and presumably related, I don't understand whether Mach is using the input to find the RPM or whether the plug in is finding the RPM and sending it to Mach to display. Thanks for any advice.