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APC doing horrible things with "standard" cables isn't new, though - they used a nonstandard null modem serial cable back in the day, such that if you tried to connect to the UPS using a standard null modem cable, it'd trigger shutting off the UPS.

This isn't to say it's good, just that it's not new.



That's always drove me nuts because the underlying issue is a great idea, frustrated by its implementation.

The serial port serves dual-purpose. Along-side the obvious serial, you can also provide some inputs by grounding certain pins, and some outputs by sinking current from others. This has got me through some unorthodox integrations by having the UPS signal that it's on battery by having these "simple signals" close a contact/relay on the load. It's not quite a full suite of dry contacts, but it's pretty serviceable.

The problem is that 9 pins doesn't leave many spare, so to achieve this they've repurposed some. I really wish they'd implemented this as an alternate mode so you'd, for example short tx to rx to change the behaviour - instead of having the 'alternate behaviour' sitting on standard DTR/RTS pins.

Getting industrial interfaces at SOHO prices was awesome. The unintended consequences .. less so.


Mine has a usb-A to rj45 cable with a ferrite bead on it, as far as I can tell it just wires the four USB wires (no ground) to the pins with spaces in between. I have never understood why they do this.

It works perfectly with apcupsd though, even showing up in my desktop power settings as a UPS.


They might be repurposing the same chassis for both USB and Ethernet-based UPSes.


Usually the APC UPS's with a network connection have a separate slot in card which has a network connection and an additional serial connection on it.


This, 100%.


It’s baffling. When APC first added native USB support to their Smart-UPS series, they chose a standard USB-B port. When they introduced “SmartConnect” a few years ago, this port was replaced by a USB-A port which requires a non-compliant USB-A male-to-male cable for monitoring. The only ‘good’ reason I can think of for this change is that someone realised that these new cloud-connected UPSes would be easily bricked by some bad firmware update (since apparently that’s a feature now), and wanted to use USB thumb drives as a recovery mechanism, but I have no idea. I think even though they have a built-in Ethernet port now, one still needs to buy their network management card for non-cloud remote management, so it could just as easily be another attempt at some weird vendor lock-in.


The pro series literally still has this exact connector today, with the same behavior.


APC was the only UPS company to have their device drivers natively included with Windows 95.

That was before USB was available so they used regular COM port communication, I'm not surprised with that early foothold there was no reason to change and sufficient force to continue ever since.

At the time it seemed like the un-necessarily non-standard RS-232 cable was just to create a "profit center" from the cables themselves, along with the non-standard replacement batteries. They sure would have been a lot quicker to market and had lower up-front engineering costs if they had used standard batteries from the beginning.

It's good to recognize early when excessively high TCO is the primary feature around which a product (or company) is designed. There can be significant PR effort from the beginning to divert any perception of anti-consumer attitude.

Lots of stealth can be involved to muddy the comparison with alternatives which offer normal TCO or well-engineered low-target TCO.


sysadmin right of passage #4


It's rite of passage [1], apologies if that was a typo or auto-correct etc.

[1]: https://en.m.wikipedia.org/wiki/Rite_of_passage


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