I'm getting acclimated with hyper-terminal and the campbell board/Mach3 settings and have the low voltage side of the drives running temporarily from my laptop to test the limit switches etc. Anyhow, starting Mach3 and jogging (with no HV to the drives), On the Z drive only, after jog the axes up, or hit the estop the red warning light starts blinking about twice a second . Onlt the Z axes does it though and switching it to one of the other axes doesn't change anything. Jogging it down seems OK. Programming is the same for all three drives and the setting is the same from what I can tell in Mach3. Makes me think it is something with the drive? Any suggestions? How does one tell wether this is a slow-medium- or fast blink? Thanks much all. Wayne