[PCW_MESA]

Yes, you _can_ use a stepgen with an averaging filter (most analog output BOBs use such a filter)
to get a analog voltage (it would generate Pulse Density Modulation (PDM) not PWM)
Compared to PWM it will be more awkward to scale

(PWM is trivial to scale, you just set the PWM scale parameter to spindle RPM at 100% PWM)

You would need to set the step pulse width long enough so that its passed without much distortion through
the isolation circuitry.

There may well be an existing bitfile that matches the Torus Pro's BOB.
So you could look through the various .pin files in the 5i25.zip from Mesa

If you had a pinout of the Torus Pro BOB I could make a specific bitfile for it
but it may well already exist

[sagreen]

Yes, you _can_ use a stepgen with an averaging filter (most analog output BOBs use such a filter)
to get a analog voltage (it would generate Pulse Density Modulation (PDM) not PWM)
Compared to PWM it will be more awkward to scale

(PWM is trivial to scale, you just set the PWM scale parameter to spindle RPM at 100% PWM)

You would need to set the step pulse width long enough so that its passed without much distortion through
the isolation circuitry.

There may well be an existing bitfile that matches the Torus Pro's BOB.
So you could look through the various .pin files in the 5i25.zip from Mesa

If you had a pinout of the Torus Pro BOB I could make a specific bitfile for it
but it may well already exist

So far the bit file I have from Brian works great except for the spindle speed. I believe if we had the same bit file with PWM instead of Stepgen on pin 16 it would work.

Scott...

[SCzEngrgGroup]

Yes, you _can_ use a stepgen with an averaging filter (most analog output BOBs use such a filter)
to get a analog voltage (it would generate Pulse Density Modulation (PDM) not PWM)
Compared to PWM it will be more awkward to scale

(PWM is trivial to scale, you just set the PWM scale parameter to spindle RPM at 100% PWM)

You would need to set the step pulse width long enough so that its passed without much distortion through
the isolation circuitry.

There may well be an existing bitfile that matches the Torus Pro's BOB.
So you could look through the various .pin files in the 5i25.zip from Mesa

If you had a pinout of the Torus Pro BOB I could make a specific bitfile for it
but it may well already exist

The Torus Pro BOB has a 0-10V PWM to voltage circuit on PP pin 16. Feeding it a Step/Dir signal will produce SOME variation in output voltage, but not much, and certainly not enough to be of value for spindle control. Scott needs to either get a bit file with a PWM output (on the order of 12kHz, IIRC - I could check what I output on my KFlop), or he needs to bypass the logic on the stock BOB with a suitable PWM-to-voltage converter, like one of the Homann DigiSpeed boards,

The VFD also needs FWD and REV logic-level control signals which are normally high, with FWD driven low when the spindle is needed to turn CW, and both low when the spindle is needed to turn CCW.

Regards,
Ray L.

[sagreen]

The Torus Pro BOB has a 0-10V PWM to voltage circuit on PP pin 16. Feeding it a Step/Dir signal will produce SOME variation in output voltage, but not much, and certainly not enough to be of value for spindle control. Scott needs to either get a bit file with a PWM output (on the order of 12kHz, IIRC - I could check what I output on my KFlop), or he needs to bypass the logic on the stock BOB with a suitable PWM-to-voltage converter, like one of the Homann DigiSpeed boards,

The VFD also needs FWD and REV logic-level control signals which are normally high, with FWD driven low when the spindle is needed to turn CW, and both low when the spindle is needed to turn CCW.

Regards,
Ray L.

Thanks Ray...

PCW_Mesa if you could create a .bit file to these specs that would be fantastic!

Scot...

[sagreen]

The Torus Pro BOB has a 0-10V PWM to voltage circuit on PP pin 16. Feeding it a Step/Dir signal will produce SOME variation in output voltage, but not much, and certainly not enough to be of value for spindle control. Scott needs to either get a bit file with a PWM output (on the order of 12kHz, IIRC - I could check what I output on my KFlop), or he needs to bypass the logic on the stock BOB with a suitable PWM-to-voltage converter, like one of the Homann DigiSpeed boards,

The VFD also needs FWD and REV logic-level control signals which are normally high, with FWD driven low when the spindle is needed to turn CW, and both low when the spindle is needed to turn CCW.

Regards,
Ray L.

Ray,

You mention above:

The VFD also needs FWD and REV logic-level control signals which are normally high, with FWD driven low when the spindle is needed to turn CW, and both low when the spindle is needed to turn CCW.

These 2 signals come out of the novakon BOB. I believe that the output of PIN 14 is interpreted by the BOB to create the FWD and REV signals. How should pin 14 be treated (HIGH/LOW CW/CCW) to produce the desired FWD and REV outputs?

Other than pin 16 (PWM) and Pin 14 (DIR) is there anything else that has to happen on the parallel port of the BOB to cause the spindle to move in the proper direction, at the desired speed?

Thanks,
Scott...