RT-8p8c - An ethernet based interface for LinuxCNC

I see, the tunable delayed reply is good!
In fact what is needed is a delayed "measurement-and-reply" not just reply, so the data used by the PID routine is as fresh as possible.

Things might get complicated managing different delays when several boards are connected, unless ring-virtual-topology is used as you suggested...

Regards,
Fernando

fmederos wrote:

I see, the tunable delayed reply is good!
In fact what is needed is a delayed "measurement-and-reply" not just reply, so the data used by the PID routine is as fresh as possible.

Yes, it's a delay before measurement and reply.

Note that ~100us is tx and rx combined. This time can be reduced if the PIC32 workload is also reduced.

Things might get complicated managing different delays when several boards are connected, unless ring-virtual-topology is used as you suggested...

Regards,
Fernando

Play with one board at a time.

Do you have any particular reason for the selection of PIC? I assume because it was the one on the demo kit?
I'm thinking of a servo interface instead of steppers, which requires more hardware (D/A, encoder tracking) but I like the approach you've taken.

Doug

jimlas53 wrote:

Do you have any particular reason for the selection of PIC? I assume because it was the one on the demo kit?
I'm thinking of a servo interface instead of steppers, which requires more hardware (D/A, encoder tracking) but I like the approach you've taken.

Doug

I actually started with the enc28j60 board that I had before progressing to the fastest ethernet enabled chip that Microchip had.

I choose stepgen because I just want to control my MF70 mill. I don't like to use the thick LPT cable.

The other nice thing about PIC32 is the built-in DMA which helps a lot if you want to offload the processing to another chip/fpga. The PIC32 just serves as a high speed bridge to whatever driver board you want to use.

GP

I have several routers using stepgen and they work great (with the big LPT cable!). I just acquired an old SMT assembly machine which has a good X-Y ballscrew/servo setup, including the servo amps. So I need a servo control interface. I would be interested in testing your board/firmware on one of my stepper machines, which will help me get familiar with the code, something I'll need for a servo interface. Can I buy a board?

Doug

jimlas53 wrote:

Can I buy a board?

Once the hardware and software are stable and tested. Everything is still in alpha-stage. I haven't hooked it up to a real machine yet; the only connection it had is to my scope.

The real motivation behind this is to actually develop a working RTnet hal driver so that the big guys can come in and start making good stuff.

GP