Dynomotion

Group: DynoMotion Message: 6851 From: chrismd500 Date: 3/2/2013
Subject: A very weird issue...
After earth grounding the cabinet I started to get some issues with "Read Failed - Auto Disconnect" when a specific set of limit switches were activated/deactivated. The issue was very repeatable and only associated with the limit switches connected to one of the two RJ45 I use for my switches. However, after swapping around the two RJ45's (the switches are connected identically on both the cables), it turned out that it wasn't the switches or the cables itself but rather something upstream of one of the RJ45 connectors on my cabinet.

After a day of trying everything it all came down to an issue with the USB extension cord I'm using. It seems like there was a bad connection at the female side of the extension cord. I could recreate the issue by putting slight pressure on one side of the extension cord female connector.

I do understand that a Read Failed can be caused by a bad USB connection, but not that the failure is only triggered by some of the limit switches while everything else works perfectly. Have anyone experienced something similar, or could explain this?
Group: DynoMotion Message: 6858 From: Tom Kerekes Date: 3/2/2013
Subject: Re: A very weird issue...
Hi Kris,

Are you powering KFLOP from USB?  A device is only allowed to pull 500ma from USB.  10~20 ma per IO can add up and exceed the limit. A poor USB connection might limit the current further.

Regards
TK


Group: DynoMotion Message: 6859 From: chrismd500 Date: 3/2/2013
Subject: Re: A very weird issue...
Hi Tom,

Yes, the kflop is powered by USB, but the limit switches are "powered" by the motor power (24v).

I just found it weird that the issue occurred when triggering the limit switches connected to one of my two RJ45 ports only. The issue never occurred triggering the limit switches on my other RJ45 port (the ports are identical but connected to different IO pins on the kstep).

--- In DynoMotion@yahoogroups.com, Tom Kerekes <tk@...> wrote:
>
> Hi Kris,
>
> Are you powering KFLOP from USB?  A device is only allowed to pull 500ma from USB.  10~20 ma per IO can add up and exceed the limit. A poor USB connection might limit the current further.
>
> Regards
> TK
>
>
>
>
> ________________________________
> From: chrismd500 <kristoffer.jensen@...>
> To: DynoMotion@yahoogroups.com
> Sent: Saturday, March 2, 2013 3:05 PM
> Subject: [DynoMotion] A very weird issue...
>
>
>  
> After earth grounding the cabinet I started to get some issues with "Read Failed - Auto Disconnect" when a specific set of limit switches were activated/deactivated. The issue was very repeatable and only associated with the limit switches connected to one of the two RJ45 I use for my switches. However, after swapping around the two RJ45's (the switches are connected identically on both the cables), it turned out that it wasn't the switches or the cables itself but rather something upstream of one of the RJ45 connectors on my cabinet.
>
> After a day of trying everything it all came down to an issue with the USB extension cord I'm using. It seems like there was a bad connection at the female side of the extension cord. I could recreate the issue by putting slight pressure on one side of the extension cord female connector.
>
> I do understand that a Read Failed can be caused by a bad USB connection, but not that the failure is only triggered by some of the limit switches while everything else works perfectly. Have anyone experienced something similar, or could explain this?
>