allus Posted September 22, 2007 Report Share Posted September 22, 2007 hi experienced LabVIEWers, I would like to do a baby step in our production. Normally, people use a Digital Multimeter (DMM), Steps 1. Move the two red and black probes around, position the probes at test points. 2. Make sure have good contacts at probe's sites. 3. Visually Take the reading 4. record it on paper (called test data sheet). To automate this without re-design the whole process, (just want a baby step) I can have PC connected to a DMM with serial port or USB. keep step 1, 2, 3 above the same, because sometimes the positioning of the probes making a significant difference in reading in step 4, I need to look for a DMM which has a "send" button so the users can send the reading to the PC. Does anybody see such a DMM or has a better way to do this. normally, I see the traffic is in the other direction, the pc sends a command to the DMM requesting DMM's data. but how do you know when the probes are in stable position to request the measured data, instead of unreliable measured data? I know that this is not a 100 percent automation, but I can save a lot of money, by using the pc to automate the process of testing for the data - in limit range , writing error and forget to write down /skipping one measurement etc... need to show some good results for buying decisions. Quote Link to comment
rkanders Posted September 22, 2007 Report Share Posted September 22, 2007 Some benchtop Fluke DMMs have trigger function that you can setup during connection. After trigger you can wait a bit and take an average or median of a couple of measurement points. This worked very well for me a while ago to measure voltages during incoming inspection. Other benchtop DMMs ptobably have the same function as well. Quote Link to comment
dsachau Posted September 22, 2007 Report Share Posted September 22, 2007 Could you have LabVIEW poll the meter until it sees a steady value in the correct range? If you wanted to get a little fancy, you could include a sketch of the board that shows where to put the probes for each measurement. Another route would be to make your own trigger, maybe something foot operated so the tech can use both hands for the probes. This would be easy to do if you have a daq card; I'm pretty sure you could rig something up using the parallel port too. Quote Link to comment
TobyD Posted September 22, 2007 Report Share Posted September 22, 2007 QUOTE(allus @ Sep 20 2007, 06:54 PM) I need to look for a DMM which has a "send" button so the users can send the reading to the PC. If the user can push a "Send" button on the DMM why couldn't they push a "Send" button in your LabVIEW application that queries the DMM for its current reading? You could also implement the timed trigger that rkanders mentioned where you push a button in your LV app that waits a few seconds and then queries the DMM for data. Quote Link to comment
allus Posted September 25, 2007 Author Report Share Posted September 25, 2007 I may look into pocket DMM with logging feature, and dump the memory storage at a later time. Thank you for the suggestions, now I have a few methods to consider. Quote Link to comment
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