Perfect, thank you Todd...
It is interesting. I've never gotten a good feeling for how many people are using the Mesa 7i77 or, for that matter, LinuxCNC. Some of the information out there is surprising bleak when attempting self-help through Google searching. I found only a few hits on getting the Mesa configured within HAL. For that matter, even the Mesa manual, which is usually pretty good at providing info, seemed a little sparse on the subject.
From a first time integrator perspective, I know I'm in the 'drinking from a firehose' mode right now, which is fine. I expected that. I've stumbled and you guys have been great at helping out. I like doing self discovery but I don't feel too successful with it in this project. I'm still bumbling around with how one links the PLC to HAL, for instance. Take the limit (in my case, the home as well, although I'll back off to the index pulse) switches as an example. I know the HAL input pin. And I have set the INI file so it will look at the index pulse. But I get the feeling that the INI file is a fairly "dumb" file that is primarily used only for configuring HAL (lots of references in HAL to INI define variables, for instance). What I am quite certain I've missed is how to bind the physical limit switch pin to LinixCNC so that it is used for homing and over-travel detection.
I get the feeling like there must be a guide out there that has all of the signals that are needed by LinuxCNC. I could then bind these to the physical PINs within my specific system. Thus far, however, I haven't seen a comprehensive document that has that information. I must be missing something.
Alan