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Bus Lock Issues

PostPosted: Sun Sep 24, 2017 4:00 pm
by tngo
It seems I'm having an issue with bus locking. I had just added a relay expansion along with expansion hub and I get a bus lock every 30 minutes. I have isolated the issue to the relay expansion as removing it gets rid of the issue. I have tried different ports on the hub but have the same same issue. Is there a way to remedy this or is it a result of the relay module becoming bad? What defines the bus lock on the head unit? Is the watchdog timer still implemented so that the head unit resets itself after the bus lock?

Thanks,
Tim

Re: Bus Lock Issues

PostPosted: Sun Sep 24, 2017 5:41 pm
by rimai
Bus lock is when an offending module takes over and doesn't let nothing else communicate through the bus.
The watchdog will not trigger on bus lock. If it did, the head unit would reboot and find the bus locked and reboot again and keep rebooting in an endless loop.

Re: Bus Lock Issues

PostPosted: Sun Sep 24, 2017 6:49 pm
by tngo
Thanks for the explanation Roberto. Would this mean that it's a bad relay module? Any way to interrupt the module in code? I'm not sure how best to remedy the issue. Would this be caused by grounding issues or something else? I'm using the original relay box with a relay expansion module. The dimming module is working fine, and they are both connected to a expansion hub. If it's related to the module then I can pick up a new one to try an resolve the issue.

Thanks,
Tim

Re: Bus Lock Issues

PostPosted: Sun Sep 24, 2017 7:10 pm
by rimai
That's what it is looking like.
Does it show any signs of corrosion?
Did you try a different usb cable?

Re: Bus Lock Issues

PostPosted: Sun Sep 24, 2017 7:55 pm
by tngo
The corrosion is more apparent on the expansion hub. On the relay expansion there isn't too much. I have switched to different ports on the hub but same issues. I'll see if changing the cables will offer better results. Would there be any issues relating to the vga cable the connects the relay expansion module to the relay box? I'll try and isolate the issue further. Any input is appreciated.

Tim

Re: Bus Lock Issues

PostPosted: Mon Sep 25, 2017 9:36 am
by tngo
I changed the usb cable but have the same issues. Going to bypass the expansion hub and have the 2nd relay expansion connected to the head unit directly to see if the issue persist before ordering the a replacement relay expansion. You still have the relay expansion modules available Roberto?

Thanks,
Tim

Re: Bus Lock Issues

PostPosted: Tue Sep 26, 2017 9:16 am
by tngo
I connected the relay expansion directly to the head unit and the bus lock didn't occur. Even with two relays connected to the head unit there was no bus lock. The bus lock only occurs if any relays are connected to the expansion hub. However the dimming expansion won't cause a bus lock when it is connected to the expansion hub by itself. Would this mean that the expansion hub has an issue and not the relay expansion?

Thanks,
Tim

Re: Bus Lock Issues

PostPosted: Thu Sep 28, 2017 9:35 am
by tngo
I replaced the expansion hub and all the bus lock issues are gone, well at least for the last 12hrs. It seems the corrosion in the usb female connectors caused the bus lock between the relay and the head unit. I am going to get some silicone usb cover caps to insert into the unused usb connectors to prevent future issues with corrosion, or at least to slow it down. Thanks for your help Roberto.

Tim