I recently aquired an APC UPS and connected it to my (Mac) server through USB. However, the load percentage is only updated (via pmset -g ps) when unplugging/plugging the USB cable. I found out it's only the DATA- line that has to be diabled for a second or so.

I wondered if using an NE555 in astable mode connected to an SPST analog switch (TS5A3157 or MAX4644 f.i.) will serve my purpose (switch off the data- line for a second or so every 30 seconds). Any info on (USB) side effects would be very helpful.

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(And yes, I've searched the interwebs, contacted APC, installed latest software/firmware et al. ;-)

Thanx in advance for any info.



At work, I've been using a programmable USB hub from Acroname to switch USB device(s) on and off using Python scripts. Apparently this hub is an off the shelf hub but pretty new (and a little expensive), and it has been very reliable for me in the lab. Not quite the discrete solution you are suggesting here, and certainly more expensive... but at work, I was looking at automating this switching and a programmable hub was a very convenient and timely find for me.


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