USB communication reliability

I have had several occurances of a print stopping for no known reason. Pronterface will respond to commands such as PAUSE or RESUME, at least until a motor command is sent - when it will display an hourglass forever. There is no warning from either window of Pronterface, or from MS windows of anything being wrong.

Can anybody tell me what can be going wrong - and how to prevent it happening again?

Thanks,

Mike

You may be getting corrupted commands.

Use a good cable, preferably one that is not too long (eg: less than 1 metre long) to avoid electrical noise causing issues.

I have one about 50cm long with RF chokes on it (the cylinder shaped pieces you see on some cables just after the connector), and it seems to work well. Longer flimsier cables have failed me in the past, so I tend to go for something that seems a bit thicker cable wise.

Note: I see some people saying that RF chokes on such cables are useless, and others that swear by them. All I can say is try for yourself and see.

Hi Cefiar,

Although I havn't totally dismissed noise on the lines, I have the mains to that end of my workshop fed through a big Schaffner filter, ditto the flourescent lights. Power supplies are 24V 10A switch mode for the motors & hot end. Hotbed is temporarily fed through a big analogue Digimess power supply as it needs 16V to get up to 110 degrees and the USB cable is 1M screened cable (no cylindrical filters though).

None of the above should give any noticable problems and the problem is quite rare, but very frustrating when it is a 13 hour build that fails at hour 10.

It would be nice if there was a way of finding out where it had stalled - e.g., something in Pronterface that said what line number was the last to be sent - along with a way of re-starting at that line.

Mike

I think, or hope, that I have found the problem. I seem to remeber that Windows is pretty much incompetent when it comes to serial communications and it seemed to be Windows that was not trying to communicaate - even after shutting down Pronterface and restarting it an couple of times. Only after rebooting the computer could Windows talk to Pronterface.

What I have tried for the moment is to reset the com ports in Windows Device manager to the same speed as the com port is set to in Pronterface. No problems so far - all fingers crossed.

Mike

You could try running Ubuntu from a memory stick/cd and see if that makes your problems go away.