Can EMC update its internal X,Y,Z according to an external reading?

[david_geng]

Hi,

I'm thinking to use EMC for my next project. However, I do not have any experience with it.

The idea is to have an MPG connected to an exernal simple controller. This controller can generate the pulses to control the motors by the MPG input, which means you can move the machine without a PC. The controller also has an interface connected to a PC running EMC. So you can use G-code to control the machine when the PC is power-on.

The question is: when the MPG and the PC are both connected, if the MPG moves the machine (e.g. edge finding), is there a way that the EMC can "see" this movement and update its internal position and the display on the screen?

Note that the MPG is connected to the external controller not to the PC. If the external controller present a mapping of the MPG to the PC parallel port, would EMC be able to pick that input?

Many thanks
David

[samco]

I think you need to explain what your trying to do a bit better.

This controller that your mpg is hooked into - what is it going to do? What happens if you spin the mpg too fast - will it know that the motors cannot keep up?

you can hook mpg directly into emc2. You can use them as jog pendons or whatever. Emc2 is the motion controller - I would rather use it instead of re-inventing the wheel. (just my opinion)

maybe I am missing what you are trying to do. Anything that moves trajectory control outside of emc - really isn't a good match.

sam

[david_geng]

Originally Posted by samco I think you need to explain what your trying to do a bit better. This controller that your mpg is hooked into - what is it going to do? What happens if you spin the mpg too fast - will it know that the motors cannot keep up? you can hook mpg directly into emc2. You can use them as jog pendons or whatever. Emc2 is the motion controller - I would rather use it instead of re-inventing the wheel. (just my opinion) maybe I am missing what you are trying to do. Anything that moves trajectory control outside of emc - really isn't a good match. sam

Sam, thanks for your input.

I hate to boot up a computer for a simple job, like drilling a few holes, split block, etc. So I want to be able to operate the mill semi-auto without the PC.

So here comes this external control sitting at the T junction of PC, machine, and MPG. I want this controller being able to take the input from the MPG and controls the machine. So the MPG works like a power steering of the machine. Moreover, when the PC is on and EMC is running, I want this controller able to talk to EMC so that the movement caused by the MPG can be update to the EMC.

I feel I need to design something like the Pluto board and take the advantage of the EPP mode. The MPG input will be read and stored in a global structure when each time the motor driving is updated. A virtual jog driver will read this data instead of from a game port.

Let me know if I'm wrong or there is better way to do it.

Cheers
David

[unterhaus]

I'd boot the computer and use emc to jog using the mpg. I saw the machinist at work milling that way the other day using a Haas. Otherwise, I don't see why they need to exchange position info when you turn on the computer. Treat them as seperate systems.