combining manual and cnc usage

Hi,
I am replacing the dc motor on my mill with a 3phase motor + inverter as part of its conversion to CNC. Here in the uk there are several companies that sell inverters together with a remote pendant. My question is can I arrange it so that I can switch between using the pendant for manual use and an output from emc when using cnc and if so how?

Is it as simple as connecting two input sockets (one for pendant and one for computer) between a 2pole multiway switch to allow me to select either one or the other?

Thanks

Alan

Hi

The pendants supplied with VFDs replace the buttons on the front of the drive for remote use. Depending where you are going to mount the inverter, you may not require a remote pendant at all.

If you do get one, the safest way would be to have an isolating switch along the lines you describe.

Generally pendants include a potentiometer control for speed which has a live feed from the inverter.

However control via LinuxCNC is generally done via a separate 0-10v connection from a speed board or similar.

The pendant will also connect to the 'Enable' line which LinuxCNC will probably use and the 'Forward' / 'Reverse' lines which it definitely will use.
Some inverters will also have torque boost features etc. but generally these days the settings are programmable rather than triggered by wired signal.

A VFD is one of the simplest ways ways of controlling the spindle in LinuxCNC, often just requiring 4 or 5 connections.

regards