NI Home > Community > NI Discussion Forums
Reply
Active Participant
chuck72352
Posts: 297
0 Kudos
Accepted Solution

Looking for an example application where more than one similar unit is tested simultaneously

I'm looking for an example application where more than one unit of the same kind are tested simultaneously on a test rack with several stations. My first thought was to use parallel loops but because some of the test equipment is being shared it's probably not the best approach.

 

Thank you.

Member
JoshY
Posts: 83
0 Kudos

Re: Looking for an example application where more than one similar unit is tested simultaneously

Hi Chuck,

 

What kind of tests are you running? Also, what test equipment is being shared? If the tests are completely independent, then using parallel loops should be okay. Depending on what test equipment is being shared and how it affects the individual test, you could use parallel loops with a wait function connected to sequence structures for the portion being shared. The parallel loops will allow the multiple units to run simultaneously while the sequence structures can control letting each unit share the test equipment.

 

Also, there is an article here of how to do it in TestStand.

Josh Y.
Applications Engineer
National Instruments
Knight of NI
Knight of NI
Ben
Posts: 16,102

Re: Looking for an example application where more than one similar unit is tested simultaneously


chuck72352 wrote:

I'm looking for an example application where more than one unit of the same kind are tested simultaneously on a test rack with several stations. My first thought was to use parallel loops but because some of the test equipment is being shared it's probably not the best approach.

 

Thank you.


 

Exactly how you go about sharing the common gear will make a big difference in how to go about doing this.

 

If the common gear can be set-up to do all of the work at once you can consolidate the functionality into a common entity that acts as a proxy to the tests or else you have to work a method of sharing the shared resource such as scheduling the resource etc.

 

So plese detail the shared equipment and how it is to be used. WE may be able to advise further based on your situation.

 

Ben

 

Ben Rayner
Who is NOT John Galt... yet... just building Rayner's Ridge

Active Participant
chuck72352
Posts: 297
0 Kudos

Re: Looking for an example application where more than one similar unit is tested simultaneously

Basically what I need to do is to  test and burn-in six dc/dc converters simultaneously. The burn-in/ test is about 24 hours during which tiime I cycle the converters off and on periodically, using different loads and input voltages, and make periodic voltage and current measurements. I'm using one Agilent E3634A DC power supply as an input for all six converters. Each converter will have its own electronic load, which is an Agilent 3300/3304. Note that the 3304 has six channels. For the measurements I'm using an Agilent 34970/ 34901 (20 channel). So the shared resource is the E3634A DC power supply and to some extent the 34970.

 

Josh,

 

I dont understand your suggestion. I"m not sure how I would incorporate the sequence structure with parallel loops.

 

Thanks,

Chuck M.

Member
JoshY
Posts: 83

Re: Looking for an example application where more than one similar unit is tested simultaneously

Hi Chuck,

 

For your power supply, is it switching in between devices or branching out to all six at once? Also, how are you communicating with the power supply? If it's branching out to all six devices at once, it's possible to set each command in order and not need to run in parallel.

 

I'm also a bit unclear when you say each converter as its own electric load and also mention that the 3304 has six channels. I'm assuming you have six 3300/3304's. Is this correct?

 

As for the sequence structures, this is sort of like what Ben suggested about scheduling the shared resources. This way you can make sure one device is done using that resource before the next device starts using it.

Josh Y.
Applications Engineer
National Instruments
Active Participant
chuck72352
Posts: 297
0 Kudos

Re: Looking for an example application where more than one similar unit is tested simultaneously

The power supply is branching out between all six UUTs at once and I intend to control it via GPIB. The 3300 is a chassis that holds a 3304 that has six channels. Are you suggesting that I should use a single loop architecture, possibly a producer consumer type to handle the user interface, or six independent loops? If you are suggesting a producer consumer loop approach, an example, if you're aware of one, of such an application where more than one similar unit is tested simultaneously would be very helpful. It sounds like to use the sequence approach I would have to use a single loop.

 

Thank you.

Active Participant
RTSLVU
Posts: 728

Re: Looking for an example application where more than one similar unit is tested simultaneously

I could not open you block diagram but I have a lot of experience with the Agilent 34970 DAQ/Switch unit.

 

These things are rally quite fast and as far as DC measurements you should be able to scan all 20 channels of the 34901 in under a second.

 

So worst case you just scan all the units when necessary and only use the measurements from the unit you are interested in at that time.

Active Participant
chuck72352
Posts: 297
0 Kudos

Re: Looking for an example application where more than one similar unit is tested simultaneously

The diagram is a Word file.

Knight of NI
Knight of NI
Ben
Posts: 16,102
0 Kudos

Re: Looking for an example application where more than one similar unit is tested simultaneously


chuck72352 wrote:

The diagram is a Word file.


 

Word files are a vector for contageon (sp?) !

 

Post images as png or jpg please.

 

"You gotta know the teritory." (The Music Man, Scene I)

 

Without the details of the rules and time affecting each widget it will be har to say.

 

Quick example:

 

NIOSH certifies filters for use in breathing equipment agains everything you can imagine. THe instruments for "everything you can imagine" can add up to a lot. To allow testing multiple at the same time the test are staggered such that a single instrument is used to sample all of the widgets. The Schedule is computed when the request to start the test is initiated such that when the widget is done being abused, the instrument is available for use by that test cell.

 

But that is an extreme case and your stuff may be different.

 

Ben

 

Ben Rayner
Who is NOT John Galt... yet... just building Rayner's Ridge

Active Participant
chuck72352
Posts: 297
0 Kudos

Re: Looking for an example application where more than one similar unit is tested simultaneously

I've attached the block diagram as a png file.