[Nut-upsuser] INELT Monolith II 1000LT

Arjen de Korte arjen at de-korte.org
Sun Jun 17 14:34:40 UTC 2007

> root at gw#/usr/local/libexec/nut/megatec -a apc -k
> Network UPS Tools - Megatec protocol driver 1.5 (2.0.5)
> Carlos Rodrigues (c) 2003-2006
> Initiating UPS shutdown
> Shutting down UPS immediately.
> But it still working and send current to output.

We've seen similar reports lately. My guess is, that some UPSes need
either a different command to shutdown (note that the 'megatec' driver
hosts a whole family of similar devices) or that we need to retry the

> How to check why UPS doesn't perform powerdown command ?

What would really help, is if you're able to run the UPS with the software
it came with (which is usually Windows) and can snoop the communication
between that software and the UPS. See if you can catch what command is
sent to the UPS to make it shutdown. Quite possibly, it will require a
different command to shutdown when running on battery opposed to when
running on mains.

You could try connecting a terminal program to it and sending the shutdown
command manually (communication settings 2400 baud, 8 bits, no parity, 1
stop bit). Currently, the commands


are sent. Alternatively, you might try




Make sure that the UPS is not powering *any* systems when trying out these

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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