Feedrate override with MPG

[foka4]

Has anyone written a brain to control feedrate override (FRO) and spindle speed override (SRO) with a MPG encoder?

It seems like it should be possible, but I'm struggling a little. I'm using an MPG through a parallel port for jog control, and it works flawlessly. I'd like to use the same MPG for controlling feedrate and spindle speed overrides, but I can't figure out how to do it.

If I have to use a MODIO module to accomplish this, I'm fine with it, but since I have enough I/O on my second parallel port, I'd like to use it instead.

Thanks,

M

[Torchhead]

That is kinda what we do with our MPG101B Hand Control. The simplest way is to pick a couple of unused pins on the port and using a macro to call the feedrate function (or spindle speed) in MACH. Just attach a button action to an input and call the function via a Macro. Our first MPG-02 several years ago used all descreet inputs for the button functions (used 11 inputs on the 2nd parallel port). Later we got cute and with a processor chip in the Pendant we used a 6 bit; Byte wide code from the scanned keypad talking to a plug-in that handled not only 16 buttons (with shift up to 28 functions) as well as two analog signals from a Jogstick. We are able to read the jogstick postion and make the pulse speed proportional to deflection. I think the pure MPG rotary dial works well on a mill but for long jogs it's pretty much a PITA especailly if you have more than one axis to jog. We used our first version for a couple of years and that drove me to design a Jogstick version than had three levels of jog speed (Fast, slow, single step) that lets me scoot around a big table in two axis at once.

To get something to call a function you have to assign it to an OEM Trigger and the OEM trigger can be physically tripped using an OEM TRIGGER on the inputs.

Drop me a line off list and I think I can scare up the old code I used and the MACH macro to read discreet pin inputs. SInce Feedrate UP , Feedrate Down and Feedrate Reset are functions that is real easy to do. I am pretty Spindle Speed canbe handled the same way.

TOM Caudle
www.CandCNC.com