Mach3 VFD PWM signal...

[Davek0974]

Should it be possible to measure the 0-10v signal?

I thought so, but I tried measuring the input to the VFD from the BOB and as soon i touched the VI & ACOM pins in the VFD the motor stopped as if the input was being shorted out?

This was with an expensive Fluke DMM on DC volts, i was expecting to see something 0 and 10v here??

Odd?

[Clive S]

Should it be possible to measure the 0-10v signal?

I thought so, but I tried measuring the input to the VFD from the BOB and as soon i touched the VI & ACOM pins in the VFD the motor stopped as if the input was being shorted out?

This was with an expensive Fluke DMM on DC volts, i was expecting to see something 0 and 10v here??

Odd?

Was it on auto ranging !! could be capacitance !!

[Davek0974]

Yes autorange but only Volts DC, it has no capacity ranges - too basic.

[Ger21]

Should it be possible to measure the 0-10v signal?

Disconnect the VFD and measure it.

[Davek0974]

will try that tomorrow, thanks

[JAZZCNC]

What you using for Speed control Dave.? On-board Bob or separate board.?

[Davek0974]

Its a cnc4you CP 0-10v breakout board with on-board converter.

I fired the question at cnc4you and just got a reply - yes i should be able to measure 0-10v there, so i have no idea why i cannot.

[Graeme]

Make sure you don't have the lead plugged into the current connectors marked "A" or "mA" - For voltage they should be plugged into "COM" and "V". Its very easy to forget.
Graeme

[Clive S]

Make sure you don't have the lead plugged into the current connectors marked "A" or "mA" - For voltage they should be plugged into "COM" and "V". Its very easy to forget.
Graeme

Yes but good meters don't let you do that. But good point. Dave: By capacitance I meant from the leads they act as a capacitor if they are very close.

[JAZZCNC]

I fired the question at cnc4you and just got a reply - yes i should be able to measure 0-10v there, so i have no idea why i cannot.

Sounds like you have dodgy Bob to me.? 100% should be able to measure the Voltage coming out the speed Controller.