Interrogating LinuxCNC for realtime information (position, etc.)

ericm wrote:

What's the best way to get realtime information about position, velocity, program line number, etc. from LinuxCNC? I want to be able to take this data and send it to another server for display on an operational dashboard. I've been poking around and it seems like there are a ton of ways to do this, but I'm not sure what would be the best.

One very easy way is to ssh in to the LinuxCNC machine and "halcmd loadusr halmeter".
I do that quite often, typically to monitor motion.program-line to see when the machine is finished or waiting for a (manual) tool change.
You can look at any HAL pin this way, and can open mutliple instances of halmeter.

A very similar way would be to create a custom Glade panel with pins that link to the HAL pins of interest, and then to load that in a remote X session on the other machine (halcmd loadusr gladevcp mypanel...).
I think that you could relatively easily have the Glade panel link its own pins, but there is also the option of having it poll linuxnc_stat
linuxcnc.org/docs/2.7/html/config/python...ding_linuxcnc_status

Or your remote widget could send linuxcncrsh commands and parse the return values:
linuxcnc.org/docs/2.7/html/man/man1/linuxcncrsh.1.html

As you say, there are lots of ways to do this. Halmeter is the least work. (because it is no work)