Increasing the maximum gcode size?

[Josh Pieper]

Is anyone here aware of the reason for the 2.5MB limit on gcode?  linuxcnc itself appears to handle larger sizes just fine... http://linuxcnc.org/docs/html/gcode/overview.html#_file_size

I inadvertently tried running a longer program, and it seemed to just silently truncate it, which wasn't a super helpful failure mode.

I'm wondering if I could, at my own risk, tweak some config on the device to try higher size limits?  I have a single adaptive roughing pass, that while I could split it up, it would be a lot more convenient not to have to mess with doing so.

Thanks,

-Josh

[Jake Danczyk]

Hey Josh,

This 2.5MB limit has been removed on our newer software updates. Use the ethernet port to connect to a computer with internet access and you'll be able to run the software update. (Software-Update-Tutorial)

The only limit post v4.0.0 is the amount of free disk space on the BeagleBone Black, which is about 1.1GB when we flash the BBB with our current production image.

The reason for the old limit:

• When a file upload is in progress, the server is locked up and unresponsive. 
• There is a "heartbeat" that occurs in the UI, which checks the server status. 
• If the server is locked up for consecutive heartbeats, the UI assumes connection has been lost, and will start trying to re-establish connection. This resulted in a number of problems if the connection was just busy and not actually lost.

The 2.5MB limit was a compromise to keep the "heartbeat" period low, so that a real loss of connection would be detected in a reasonable time frame.

The solution we went with was to upload files in chunks. Running GCode directly off a USB thumb drive is also in the works.

Regards,
Jake Danczyk

[Josh Pieper]

Jake,

Thanks for the detailed reply!

As it turns out, I had misdiagnosed my problem.  I actually already have a post v4.0 firmware and wasn't hitting a file size limit at all.  Instead I was exceeding the travel limits on the Z axis.  The program just faulted at a much earlier point in the program so I didn't connect the dots.

Regards,
Josh