Testing devices that "may not" have a date!

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An Electrical Engineer asked me if I can find devices that have a date that is unknown to the average user or can not be accessed by the average user.

A date function, for example, in the devices initial setup or synchronised by another device or system. By the average user I mean, someone who programs the device by using the supplied user manual, not a technician with intimate knowledge of the system.

Most engineers I work with believe that if you can not "see" the date, it does not have one, so therefore why waste my time testing it.

This I believe is the case with most devices that do not have dates available for use. But there must be some devices out there that include a date or date register that do not offer it to the purchaser/user.

Can anyone help me with my query or point me in the right direction? We need proof to encourage a few major people to start testing. Time is already running out.

Thanks, Kim

Asked by Kim Smith (kim.smith@

-- Anonymous, April 12, 1998

Answers

When examining devices for Y2K compliance, you must look at both input and output from the component. Some of the PLCs in use, do not appear to have date functionality but can be connected to computers. The tester must ensure that the software in the computer isn't passing information to the controller which may cause it to fail.

-- Anonymous, April 27, 1998

This is really more of a question than answer. When it comes to embedded systems, I'm very much a layman. Recognizing that such devices must be tested, how should the testing be conducted? Is it a matter of examining output? If all you do is examine output, there may be a clock in there anyway. I keep wanting to find a way to be able to hear the clock ticking inside the box. Are there tools/techniques to do that?

-- Anonymous, May 01, 1998

A few examples of embedded system with not obvious dates.

Smart Transmitters. The Rosemount 3051 smart pressure transmitter still looks like an old fashion 4-20mA Dp transmitter, still transmits a 4-20Ma signal, but also can communicate information (typically for calibrations) on a modulated waveform riding on the 4-20Ma signal using a special HART Communicator. A date is stored on the transmitter in this example (but it is not incremented and does not appear to be a problem).

A UPS manufactured by Solid State Controls has a hidden clock (I don't have model number handy). This is sort of a special case. If the cadillac version was ordered, the clock would be apparent to a user. If a cheaper version is ordered, the clock is still installed, but not user interface is present, and it appears to be unusable (and hopefully not a problem - not confirmed yet though)

-- Anonymous, May 12, 1998


not obvious dates with remotely potential date functionality - elaborating on Fred's answer.

Regarding the Rosemount "smart" transmitters, it is my understanding from vendor manual review and discussion with the manufacturer, that the date field is user configurable and holds a single "date of significance" e.g. my wedding anniversary. The date information is non-functional. There is no relationship between the stored date and the functioning (output) of the transmitter. Also, the Rosemount "smarts" do not use a Real Time Clock. Of special interest, however, is the digital signal riding on the standard 4-20 MADC analog output signal. That digital signal, in HART protocol, simply contains a real time representation of the transmitter's model and tag number, the process variable in engineering units, and the output current e.g. "I am transmitter 1PT207, and I am sending you 12 MADC representing 250 PSIG. NO PROBLEM, at least at this level. And this is fairly standard for the nuclear industry.

There is a REMOTELY POTENTIAL problem, however, at a different level. Keeping in mind that this "smart" transmitter's user configurable "date of significance" field is accessed by progressing several levels into the programming (configuration) menu then it is possible for, say, a distributive control system (DCS) to actually "reach down" into the transmitter, retrieve the "date" and utilize it for some sorting or calculation. I have verified, in discussion with a DCS manufactuere, that this is possible. We had not heard of reports of that actually happening, and together could not conjure up a good reason to do it.

So in the secondary analysis, it is remotely possible, but very unlikely, that one could make functional an element which was not designed for functionality - "date of significance" in this case.

My opinion is that you must assess every component, and if there is doubt, perform an indepth assessment. Keep in mind that assessment of design is not the same or as valid as testing.

Lightfoot Clark

-- Anonymous, May 20, 1998


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