I now have added a relay and can turn the spindle on/off from Mach4. Since doing this it seems Mach4 now has no feedback as to what the spindle RPM is.
This causes the pause on start not to work in the spindle setup screen and also trying to check the box that says wait till spindle is at 90% does not work either.

Do I need to add a wire to monitor the spindle speed that the Hitachi VFD is commanding so it can be read in Mach4 or am I missing something else?

Hi,

Since doing this it seems Mach4 now has no feedback as to what the spindle RPM is.

How is Mach supposed to know how fast the spindle is going? It knows that its been commanded to go to 15000 rpm say, so it produces
PWM to suit, but it has no idea whether the speed has been reached or exceeded.

Any setting like the '90% of target speed' that relies on some measurement of speed is going to fail UNLESS you provide that measurement.

If you really want to know what the spindle rpm is then you'll have to supply an encoder or a index signal on the spindle, the ESS will detect
this signal and feed the information back to Mach. Then Mach would have an exact speed measurement to display. The ESS can also accept the feedback
and vary the PWM a little under a PID loop.

Do you really need it?. For years and years we used manual mills and lathes and they never had spindle speed displays and yet we still did plenty
of good work on them, so why the insistance  on knowing exact spindle rpm now?

There is another possibility which may allow you to pause until the spindle is up to speed. There is an input signal in Mach....ISIG_SPINDLE_AT_SPEED.
Note this is a signal defined in Mach....it does not do anything UNTIL you hook it to some external signal source, its just a convenient definition at the moment.
Most VFDs can be programmed such that one of  their digital outputs goes high when the spindle is at its commanded speed. Now you can program the drive,
hook the digital output to an input on your BoB/ESS combo, and then logically attach the pin to ISIG_SPINDLE_AT_SPEED. Then you can use that signal
to program Mach.

Quite frankly it seems like a lot of messing around just to save a second or two on the spin-up time of the spindle. My spindle winds up to about 18000rpm
in three seconds and gets to 24000rpm in 4-5secs, so I program:
m3
g4 p3
and that gives me a fixed time delay which is good enough for me. I have lots more important things to do on my machine and even more important things
I need to do WITH my machine than worrying about this.

Craig

Makes perfect sense.
Did you add the pause in your post processor or can it be set in Mach4?

Hi,
the code is in the Gcode file, so postprocessor.  It could conceivably be programmed as part of the m3/m4 spindle macros.

Craig

Okay Thanks Again!!!!!
I will add it to my post processor.