Power Fail restart of SCADA File Server


Thread Starter

Peter Whalley

Hi all,

We have a SCADA file/data server running Win NT and connected to a small SOLA 325 UPS. The PC is a no-name unit with an ATX PSU. (ie soft on/off

Does anyone have suggestions as to how this should be set up to automatically restart following both short (~few minutes) and long power

In particular, the UPS has a serial connection to the NT server which signals NT to shut down after a few minutes of mains power loss or if the
battery voltage is getting low. This works OK but when mains power is restored before the UPS has shut down, the NT machine needs to be manually
rebooted. Can NT be configured reboot in response to some type of signal from the UPS. Any suggestions on which UPS can provide this if the SOLA unit does not.

What happens if the mains is restored whilst NT is shutting down. We can't just stop the shut down nor can we reboot straight away. Is their a way to make NT continue the shut down and then automatically reboot when finished.

If the mains outage is extended and the UPS shuts down and then later restarts, the NT machine does not currently restart. Someone must press the power button to start it up. Is their normally a BIOS setting or jumper setting that can configure the PC to automatically come on when power is

When NT is rebooted, a user must log in before some of the software applications can start up. Can NT be configured for auto log in?

Does anyone have a reliable proven set up of this type that works reliably in all circumstances?


Peter Whalley

Managing Director
Magenta Communications Pty Ltd
121 King Street,
Melbourne, VIC 3000

e-mail: [email protected]

Alex Pavloff

> When NT is rebooted, a user must log in before some of the software
> applications can start up. Can NT be configured for auto log in?

I don't know a way to auto-reboot an NT box, but if you use TweakUI (search Microsoft), you can automatically logon. It does place the password in plaintext the registry though, so it ain't the most secure thing.

Mark Fairbaugh

I may be missing something here. If the server is a file server then I am assuming that the SCADA system just needs access to files stored on it?

If this true then you just need to ensure that the Server service starts automatically and when the machine reboots the SCADA system should be able to access the files it needs.

The file server I use never has anybody logged onto it. It is always on with the logon screen showing and we can access any of the files from any of the workstations.

Mark Fairbaugh
PT Newmont Nusa Tenggara
Sr. Process Control Engineer
e-mail: [email protected]
Phone: (62)-370-636-318 Ext. 47948

Kirk S. Hegwood

Microsoft has a resource kit for NT that you can purchase. The kit has a Autolog.exe that will work. Go to Microsoft's web site for more info.

Kirk S. Hegwood
Signing for Hegwood Electric Service, Inc.
I've run into a similar problem when using a PLC-5 and a UPS. We ended up putting a time delay relay in the circuit so no matter how short the power interruption was, the processor had a fixed time period without power to fully shutdown and then properly startup after power was restored.

In this case, I would trigger the time delay after the shutdown signal is sent to the NT box, keeping power off the UPS until after the timer finishes, regardless of the condition of the mains.

Others on the list have addressed the login issue and I can't add anything that could help.

Russ Kinner
AVCA Corporation
Maumee, Ohio USA

Peter Whalley

Hi all,

The server runs data server applications including Echelon's LNS (the control network is based on LONWorks), the LON/OPC server from Innovex and AlarmWorX and TrendWorX servers fron Iconics. The log in requirement has to do with logging in to the network NT Domain Server so that OPC/DCOM will operate correctly across
the network.

Thanks for the pointers to Microsoft's site. We'll follow these through and see what can be done. I have also found that there is a BIOS setting that determines if the PC will come On after power up, stay OFF or Resume it's previous state so this looks like it's solved.

The major remaining issue is managing the shutdown process. Particularly what to do if mains power is restored during NT shutting
down or after NT has shut down but before the UPS shuts down. At present NT just shuts down and sits there with a little message saying it is OK to turn off the power. To get it to reboot we must
either hit return (manual intervention) or cycle power off and on. Looks like we need the UPS to issue a reset command to the file server after shut down completes. So how does the UPS detect
that shut down is complete and how does it issue a reset?

Any comments would be appreciated.


Peter Whalley

Managing Director
Magenta Communications Pty Ltd
121 King Street,
Melbourne, VIC 3000

e-mail: [email protected]

Johan Bengtsson

If you use the built in UPS service you get a signal back from the computer at one of the RS232-pins that the shutdown is complete. It is normally used to make the UPS shut down entirely to save the remaining battery for later needs instead of just discharging it.

When speaking about this: I have another problem regarding automatically UPS shut-down. When our NT4 server is shutting down due to power failure it sometimes don't shut down. I found the reason to be that one program is crashing during the shutdown. NT sees this and launches Dr Whatsson. Dr Whatsson sees that NT is shutting down and displays a message similar to "Can't start since the system is shutting down". Of course this nice box prevents the shutdown sequence and
after a while the UPS die. I have absolutely no idea what program it is that crashes.

/Johan Bengtsson

P&L, the Academy of Automation
Box 252, S-281 23 H{ssleholm SWEDEN
Tel: +46 451 49 460, Fax: +46 451 89 833
E-mail: [email protected]
Internet: http://www.pol.se/