I had my 3 axis system connected and running fine, but decided to add a 4th axis and rewire my controller to make room for the additional motor amp (all motor amps are Copely 306A). These motor amps take a +/- 10V signal for the input rather than a step and direction signal. I had my limit switches connected only to the motor amps in the old system, and therefore Mach3 was not aware they existed. If any axis hit a limit, the motor would stop for that axis only until it was commanded to move away from the limit, but Mach3 would continue running the program as if nothing was wrong. This led to some interesting shaped parts at times but not exactly what I wanted of course.
My revised controller now connects the limit switches to the Galil ICM 1900 break-out board, and uses the AMPEN(x,y,z) pin to enable the motor amp. The motors, encoders, and limit switches were set up using SmartTerminal to get all motors running the correct direction, not running away, and stopping when they hit a limit switch. I only have limit switches connected to the X,Y,&Z axis. I did discover that I got an error22 in SmartTerminal when the unused limit switch connections were not grounded for the FLSW and RLSW pins on ICM 1900. Do I need to ground other unused limit switch pins?
I then set up Mach 3 and the Galil plugin to match the configuration, but was not sure if my limit switches are active high or active low. I mapped them to the appropriate Mach3 pins per the instructions in the GalilPlugIn.pdf file. When I look at the Mach3 diagnostic screen, I see the limit switches all activated if I configure them as active low in the Ports & Pins setup screen, and not activated if I use Active high.
In either active high or active low, when I reset the controller and try to move a motor, I get an error message about limits and the motor does not move. The motors come on and lock in position when I perform the reset, just no motion. I may have selected the wrong limit switch condition when configuring the Galil plugin, but am unable to run configure a second time without locking up Mach3.
A simplified schematic showing the old and new limit switch connections and the ICM to motor amp connections is attached, along with the limit switch mapping for the GalilPlugIn.