[Nut-upsdev] Four UPS's via usb.

Arjen de Korte nut+devel at de-korte.org
Fri Feb 1 07:52:15 UTC 2008

> Hello everyone. I try to connect four PowerMust 2000 ups's via usb to one
> computer using megatec_usb driver. But megatec_usb completly ignores port
> directive in ups.conf, I even try port = /dev/null and megatec_usb founds
> ups and it works.

The 'port' is not used for USB connected devices, it's only needed for
compatibility reasons.

> Problem is that megatec_usb seen only one ups not four, and
> for four differend sections in ups.conf it uses only _one_ ups.

Apparently, the driver can't tell the different device apart through the
regular expressions that (may be missing) in 'ups.conf'.


> bus directive not work becouse i have only two buses and all ups's sits at
> one:
> data:/etc/nut# lsusb
> Bus 002 Device 001: ID 0000:0000
> Bus 001 Device 004: ID :5161
> Bus 001 Device 005: ID 0665:5161
> Bus 001 Device 003: ID 0665:5161
> Bus 001 Device 002: ID 0665:5161
> Bus 001 Device 001: ID 0000:0000

You could change one device to another bus and would be able to support
two of these devices on the same server (but not four).

> serial directive not work becouse it 'unknown':
> data:/etc/nut# upsc ups4 ups.serial
> unknown

That is due to a limitation in the 'megatec_usb' driver. Still, the
chances are remote that your UPS'es support serial numbers. One way to
find out if it does, it by using 'lsusb -v'. Most likely, this will reveal
that the serial numbers (if existant) are all the same. In that case, the
only remaining option is to connect all devices to a separate bus (adding
hubs won't help you here, the only way to distinguish them will be through
the bus directive in 'ups.conf').

Best 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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