Hi,
most VFDs are fairly similar and a number of control strategies are common.
First question to ask is 'what sort of control I require'. It is common, I've done it myself, spent lots of time and money on a really good spindle control
setup only to find that I don't use a tenth of its potential.
I use my high speed spindle for engraving mainly in which case I set it to run at max RPM and leave it that way until the job is done. At best I need only to
turn it on or off.
Do you really need for the spindle to go backwards? I made my setup so I could but I don't use it....so why did I bother? It was a waste of time.
Sometimes its necessary to have the spindle at less than full speed but it will stay at whatever speed you set for the duration of the job. You could have the ESS/BoB
set the speed but it could also very simply be set with either a potentiometer or the VFD control pad.
If you are changing tools during the making of a part it may be necessary to have the spindle run at several different speeds throughout the job and then some
sort of automatic/programmable speed control becomes desirable.
With VFDs there are two common ways to achieve that sort of control:
1) Use an analogue control voltage, usually 0-10Vdc derived from PMW from your controller
2) Using Modbus wherein serial digital signals are sent to your VFD over a two wire circuit known as RS485
For simplicities sake analogue control is preferred. If you like a programming challenge then Modbus is good.
My suggestion would be to start off at the simplest, that is on/off and maybe reverse with manual speed control. Once you've got that working then
maybe try PWM control. What I don't recommend is jumping in the deep end with a really ambitious plan when you don't know how, you'll get really
frustrated at end up learning less than if you start simple and work your way up.
Put your thinking cap on and decide what you want/need and then you can make plan how to do it, let us know what you decide.
Craig