Hello everyone. I work for a small electronics company and would like to minimize field failures with better test procedures. we were looking at trying to come up with an application that could be used to record answers to questions that would fit with the PCB.
Has anyone done anything similar to this? And if so, what were the types of questions you tracked?
Welcome.
What part of the world? (location helps some times)
I don't understand if you want a test machine or you want to add these functions to your board.
You MIGHT be going about it wrong. Why not store whatever you need in say an I2C FRAM as the errors occur. then read it when the board comes back for repair?
Hi Matt,
I think you are describing what is known as built in test equipment (BITE) and built in software tests (BIST).
I worked for three years on the BITE/BIST for a large ground RADAR system.
The first thing to know is that it is not a trivial exercise, and as a rough rule-of-thumb you can say that BITE/BIST will constitute at least 30% of hardware, software, real estate, and costs.
Very often the BITE/BIST has to be more sophisticated than the function being monitored. Take a simple example: a certain voltage in the system is accurate to +-1%. That means that the BITE monitoring that voltage needs an accuracy of +- 0.1% and preferably better.
Theses days the results of BITE/BIST can be stored locally in non volatile memory, as has been said, or communicated back to base via the net or over the air.
Often the user needs to see the results of BITE/BIST, for example if the equipment is overheating and it needs to be turned off.
One last bit of advice, BITE/BIST needs to be integrated with the design of the equipment from the inception- it can't just be glued on once the equipment has been designed.
spec
I will take a look at BITE/BIST and see what we can do with it on our end.
Thanks. being a small company, we have to look at costs and trying to keep them down. But if something costs a lot up front but in the long run will save money, it is a good investment. But only time could tell on that.
United States - Pennsylvania.
The boss is looking for something that can be a sort of checklist type of thing. Right now, some of the guys are just saying things are working, and then something fails and he doesn't know who to talk to about why it wasn't caught.
Before we go about and make up a sort of checklist, we wanted to check and see if there are others out there that are doing something to check certain components before inserting into the boxes.
What you are talking about is a 'Test Specification', which is mandatory in many areas. The purpose of a test specification is to define a procedure that will test all the functions that a particular equipment is required to perform (of course you can't do this 100%).
All tests are numbered and a 'Test Result Sheet' is produced for each equipment that is dispatched to the customer. Part of this is that each equipment as a minimum, has a name, reference number (normally the drawing number), and a unique serial number, all of which are also recorded on the test result sheet.
Take a very simple example:
An piece of equipment is a precision voltage reference of 5V with the following characteristics:
(1) Voltage output: 5V
(2) Output accuracy +- 1%
(3) Output current: 0A to 10mA
(3) Mains voltage range: 115V to 125V RMS @ 60Hz
(4) Temperature range: 10 Deg C to 50 Deg C
The test specification would list the test equipment needed to complete the test procedure:
(1) Digital voltmeter (DVM)
(1.1) Input impedance: 1M Ohm or greater.
(1.2) Accuracy: +- 0..1% or better
(2) Ammeter
.... and so on
The test procedure might say:
(1) Connect the DVM (1) to the the output terminal of the unit under test (UUT).
(2) Turn the UUT on
(3) The voltage indicated by the DVM shall be between 4.999 V and 5.001V (record result)
... and so on.
Once the test procedure is completed successfully, the test result sheet is then signed and dated by the person carrying out the tests. The test result sheet is then archived in company records.
The above is a gross simplification, but once you have a template set up for your company's test specifications and test result sheets, it gets a touch simpler.
I have spent many an hour writing test specifications for all kinds of equipment.
spec
PS: a further development to the above is automatic test equipment (ATE) and automatic test procedures (ATP), were a machine does the testing automatically.
No probs Matt.Thank you. I wasn't sure what to call it. Test Specification makes sense.
No probs Matt.
spec
PS: if you put 'Pennsylvania US' next to 'Location' on your user page, it will show in the box at the left of your posts- that will be a big help to us.
Entire books have been written on this subject, in fact I have a very good book entitled "Building A Successful Board Test Strategy" By Stephen F. Scheiber Publisher Test and Measurement World.Hello everyone. I work for a small electronics company and would like to minimize field failures with better test procedures. we were looking at trying to come up with an application that could be used to record answers to questions that would fit with the PCB.
Has anyone done anything similar to this? And if so, what were the types of questions you tracked?
To give an example, we would like to know what the reading on the meter was when power was on. Or also record the number of times the LEDs flashed and that determines the different states.
Any information that others have would be beneficial.
Thanks.
Ah, yes: 'bed of nails'.Don't forget the "bed of nails", Pogo Probes, probing as well.
Good input there SpecOne of the problems with testing is that engineering tend to write the test specification and production do the testing, and in all situations where one person dictates and another person does the doing, there are problems. One way to improve the quality of the test procedure and tests specifications is to get the engineer writing the test specification to test the first batch of UUTs.
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