[Nut-upsuser] Unitek iZi UPS 525

Arjen de Korte arjen at de-korte.org
Tue Dec 26 09:59:38 CET 2006

> I've got an Unitek iZi UPS 525 with a serial interface. The supplied cable
> looks fairly simple: RX->RX , TX->TX and GND->GND. Using this cable and
> Minicom with 2400 8N1 I'm able to issue commands to the UPS using the
> "Megatec Protocol" http://www.networkupstools.org/protocols/megatec.html
> so I know the UPS is fairly "intelligent" :-) and the serial connection
> works.


> Questions:
> 1. Which cable should I use for "Megatec Protocol"? Yes, I've read the
> aforementioned document but the hardware spec they give there doesn't look
> OK to me: e.g. "RX   <----------   TX  (pin 9)"... Pin 9 is supposed to be
> RI, or not? :-|

The cable you used for testing. Sometimes manufacturers make special
cables, so that you'll have to buy them from them (for a premium). In
other cases, a straight through connection like you used, is fine. Note
that the document you're referring to lists a specific UPS model, it
doesn't state that all devices using this protocol use this pin layout.

> 2. Which driver should I use for "Megatec Protocol"? The only Megatec
> references (in "UPS features and support"
> http://www.networkupstools.org/compat/stable.html) are for "genericups
> upstype=21". Trouble is, "genericups" looks more like an enclosure type of
> driver rather than a smart one. It starts OK but OL and LB are always ON,
> no wonder since the cable has only three wires. :-|
> Any hints?

The compatibility list you're referring to is outdated. There have been
quite some changes recently (also in the new megatec driver) and nut-2.0.5
will be released in just a couple days from now. If you can't wait for
that, grab it from the SVN trunk.

> PS. As per "UPS features and support" I've also tried "fentonups", just to
> be on the safe side although to me "fenton" looks more like a simple
> ON/OFF signaling rather than a complex serial protocol.

The new megatec driver replaces many older drivers (including fentonups,
if memory serves) with much more functionality.

> PPS. Yes, the UPS has "Linux" written on the box and they do provide some
> kind of daemon, it's just that it requires JRE and X! =:-o

The 'Linux' support for many of those system, usually comprises of a
closed source driver for ancient Linux distro's. Don't count on it if it's
written on the box, unless you're bying MGE which provides excellent Linux

Regards, Arjen
Eindhoven - The Netherlands
Key fingerprint - 66 4E 03 2C 9D B5 CB 9B  7A FE 7E C1 EE 88 BC 57

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