Powerup / Powerdown data logger?


Thread Starter


List Members,

My company makes high-speed paper finishing equipment (think: mailing machines). Production rates, service costs, downtime, etc. are all of paramount importance to our customers.

To better serve the needs of these monitoring and measuring folks, (and perhaps to cover our own rear ends), I'm looking for a power monitoring solution. Our machine *is* computer controlled, and we could record bootup times and times our software is running, but that is not always enough to satisfy the truly retentive folks. Also, the computer could be hooked to a separate supply, or our software not running even
though the computer is on, etc.

Is there a not-too-expensive device can be used to (or be programmed to) record power up and down cycles, and to transmit the history list (upon request, not automatically) to another computer via the serial port? Remember, the power may cycle up and down several times before the host reads and clears the history data, so
it should be able to timestamp and log a good number of on and off events. Because we want to timestamp power-down events, it should be either battery powered, or be able to record the "last conscious moment" prior to shutdown. Obviously it needs a realtime clock (or be able to read
whatever clock signals are available via radio waves or power lines).

We could probably roll our own little gizmo with the ubiquitous PIC chip with RTC and EEROM or something like that, but I was wondering if a packaged system might be available (even a mini-plc might suffice, or perhaps an inexpensive paperless datalogger). I'm off to check the z-world/rabbit family, but if anyone out there has
an idea, I'd appreciate it.


Remember - the device has to hold multiple items of data through one or more power-downs.

Michael Griffin

I think you are looking for an "event logger". There are a number of these on the market. They are generally battery powered and can store several thousand time stamp "events" which can be later down loaded to a PC. You want one which will record both "on" and "off" events. Most are used for enviromental monitoring (e.g., rainfall), but some are also advertised as being useful for monitoring machinery, so I imagine your application has been done before.

Below are a couple of web addresses for two different types of event logger. I haven't used either, so I can't recommend one. I am sure you could find more with a web search.



Michael Griffin
London, Ont. Canada
You could check out the SQUARED Powerlogic offer.

It is a range of devices and system designed to monitor power.

With a powermeter like the PM650 you'll be able for a low price to log the events and communicate through a modbus serial port.
For more details you can look at :

I hope it helps.