I am just starting to set up an Emco Mill with Mach 3 software. New stepper motors and drivers are being fitted. I intent to drive the spindle motor with a Siemens Micromaster inverter which can be set for analogue input 0-10V giving control of frequency/speed. The inverter also has a control input for an on/off switch.
I would appreciate advice on how to interface the inverter with the Mach 3 software using the PWM feature to control the spindle speed.

I have used the spindle speed board from Bob and I know cnc4pc has one...

Hi Geoff,

I also have a Siemens micromaster which is going to drive the  spindle motor on a Bridgeport.

So far I have Mach3 switching the motor on/off and I can see the PWM output on the breakout board.a
I intend to use a PWM to V converter module to IP the analogue in.
Module is a Siemens Siemens Sirrius Konverter 3RF2900-0EA18.

Shame the inverters cant be configured for PWM (or does anyone know different?).

Regards

Derek.

Hi Derek,
Thanks for your comments. I contacted Siemens UK and asked the question. They have forwarded details of the Sirius solid state switching device. 3RF2900-OEA18
I am not clear how it would achieve what we want. It is described as follows :- "Analogue control signals are converted into a pulse width modulated digital signal. The strength of the analog input is converted into an ON and OFF swithching time within a fixed duration of 1 sec."
This appears the reverse of what we require. Am I missing something ?

Regards,

Geoff

This is the circuit located somewhere on the Mach site. It will convert the 0-5v PWM to 0-10v ( Nonisolated.). Some of the new drives will accept a PWM input, either 5 or 10v, based on parameter settings.

Darek

This appears the reverse of what we require. Am I missing something ?
Regards,
Geoff

Hi Geoff,

I had another look at  the data sheet and you are correct !
Thanks, you have saved me a few quid.
Siemens must have a similar module though, PWM -> V
The schematic of the converter posted below looks "simple enough"
I might have a go at that if no low cost ready built modules available.

Derek.