Need some Automation Advice - Simple Auto Measurements

Started by Hawaii596, 08-29-2010 -- 18:02:06

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Hawaii596

08-29-2010 -- 18:02:06
I'm going to be automating a set of measurements as I'll describe below, and solicit some thoughts about the simplest way to do it.  We have Metcal, NI software and other methods.  But this will have to be made from scratch, and it will involve taking some simple DC voltage measurements a couple of times a day, and logging them...

THE MEASUREMENTS - I have numerous 10 VDC references that I will connect in an array through an HP 3488A with (if I recall correctly) a 44470A card.  I want to take DCV deltas between various combinations (cell 1 vs 2, cell 1 vs 3, etc.).  I won't go schematically into the whole setup. 

But basically I'll send a switching command to the 3488A to set up each measurement and send it to the input of an HP 3458A (I may swap to HP 34420A later).  I'll Include some wait statements to let the reading settle for around 5 minutes, take the reading, reset and go on to the next reading.  I'm going to do this 2 or 3 times a day, 7 days a week for months (to plot drift of the cells relative to each other).  So this will bee much too cumbersome and time consuming for manual.  I have the commands (manual) and wiring etc. all figured out.
But I want to log all the readings in a text file or Excel spreadsheet, or something including date and time of the reading. 

What I'm trying to decide is what would be the simplest for doing this.  Should it be a Metcal program, or write a macro in NI software, or what ever else.  I don 't have full labview, and I'm not a skilled programmer.  And I don't want to kill a lot of time writing this simple of a routine.  So I figured I'd pout the question out to see what you all think.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
Lord Kelvin (1824-1907)
from lecture to the Institute of Civil Engineers, 3 May 1883

ck454ss

#1
08-30-2010 -- 06:10:07
Personally Id use the NI software.  Many of the functions you need are already available with the software and its modules.

michthai

#2
08-30-2010 -- 06:52:37
Metcal does have read and write commands that allow you to read/write directly from/to Excel.

Hawaii596

#3
08-30-2010 -- 15:34:06
It doesn't necessarily need to go directly into Excel.  If we can make it output to a text file, I can import it periodically into Excel.

I think we have beginnings of a MetCal program in progress.  I did see where the tech working on it has some readings from the 3458A going into a memory location in Metcal.  I may want to let the tech continue on for a while and see where the snags are before asking for help.

If we don't have labview, just the NI GPIB software (the kind you have when you're running MetCal), does it allow you to write and save files you can use to automate and log readings into a text file?
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
Lord Kelvin (1824-1907)
from lecture to the Institute of Civil Engineers, 3 May 1883

Lee.metrology

#4
08-30-2010 -- 22:23:02
You brought up labview and that you didn"t have the full virsion.  Labview controls the data and converts to Excel very easy.  What version do you have and I would like to help. . .

Hawaii596

#5
08-31-2010 -- 08:30:59
I think we just have run time version that comes with MetCal.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
Lord Kelvin (1824-1907)
from lecture to the Institute of Civil Engineers, 3 May 1883

Hawaii596

#6
09-01-2010 -- 09:58:26
Some more thoughts and questions....

We're thinking we'll start with a Metcal procedure that outputs to a report.  Then export the report.

BUT...  it came up that if we run it 24/7, it will tie up a license permanently (as long as it is running).

So we'll probably use the MetCal method as a stepping stone (if nothing else, to begin getting some data gathered, and to assemble in Metcal format the GPIB command strings we'll need).

I remember some discussion about using Excel for GPIB measurements.  Can someone enlighten me on how this is done or direct me to where to learn about it?  Or, maybe some tips regarding what is minimally required to run in NI software.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
Lord Kelvin (1824-1907)
from lecture to the Institute of Civil Engineers, 3 May 1883

CalLabSolutions

#7
09-03-2010 -- 00:22:09

Keep in mind that if your MET/CAL Server shuts down for any reason over that 24/7, you will loose all of your data.

If you are looking for a solution that will run 24/7 looking at the data like that, I recommend you get a data logger of some kind.  The advantage is that it will run 24/7 then once a day you would log in and down load the data..

I see you are using a 3458A.. If accuracy is an issue, I would recommend you use a NI (or some other companies) Real Time Embedded Controller.  That would allow you to build the data logger in hardware.  That would be the fun / really cool solution, but it will be some work and be a little pricey.

Outside of MET/CAL (and in a real programming language) you would write a service to collect the data a periodic intervals. It would run as a terminate say resent application on the workstation or server.  If the computer is on, it would log the data.. (We did this would our automatic E-mail notification package)

Well that is my 2 cents.

Michael L. Schwartz
Automation Engineer
Cal Lab Solutions
  Web -  http://www.callabsolutions.com
Phone - 303.317.6670

calibr8tor

#8
09-03-2010 -- 06:02:17
Make sure to reverse your connections to compensate for lead resistance. The Data Proof program worked great for us when I ran the volt program. Is there really a need to run this program 24/7, or can you just manually start the program once or twice a day during the week?

Hawaii596

#9
09-03-2010 -- 09:48:27
See.... this is why I ask you folks here about these things.  I have a lot on my plate besides this (it is a "project", so I can't spend too much time on it). 

Let me respond to some of the remarks.  I'm basically trying to kick start this with items from the boneyard.  We have some HP 3488A boxes and some of the cards that are still "new" in the box (and by "new", I mean 10 - 15 years old).  So I figured I would start gathering some data to get things going.

I recently visited a very nice standards lab that has a bank of numerous brand new 732B's, and they are running a Data Proof (I believe model 160B or something like that).  So my 3488A is to plug along until we get out of this economy, and I can get funding for a new data proof box (which I understand has software with it).  Meanwhile, I'm going to look around for some freeware to run the 3488A with.  The nice thing with the 3488A (with a 44470A card) is that I have a dedicated output line to the 3458A (always on), and I can multiplex various channel combinations pretty simply.  So all I need the software to do is run the 3488A and log the readings.  What we're thinking of doing to begin with is run a Metcal program, but not 24/7.  Set it up to run once, or continuously - we'll have to think about that.  And have it generate a report which we can then export.  And I can convert it into Excel format.  That will get us started.  Then once I can either get sopme freeware or find some low cost alternative, create a simple GPIB application that will continuously run it.

Good thought regarding the datalogger.  I actuallly think I may have a working Fluke Helios in the "boneyard."  I may have one or two of the ones that look sort of like an 8842A shaped case the Hydra series, I think.   I need enough channels for nine cells.  That's the challenge.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
Lord Kelvin (1824-1907)
from lecture to the Institute of Civil Engineers, 3 May 1883

Orbireewedo

#10
11-11-2010 -- 04:07:17
Oh man thats great any chance you can get these from hobbycity? 

How long of flight times? yeah i definitely need to get better smaller electronics.  Thanks for the tips/info man
_________________
hxxp: www. ps2netdrivers. net/manual/lg. rh7521w/

RFCAL

#11
11-12-2010 -- 10:20:01
use the Hioki data loggers--10 channels--they work great and are cheap.look at testequity.com and search for Hioki

PMEL

#12
07-06-2011 -- 16:22:24
Hawaii596 I sound like a broken record today but I did write a software package to do just what you are asking. I would be very careful using a 34970A as my switching unit. I did extensive testing and found that the 34970A with any card would drop voltage. I ended up using a Data Proff Standard Cell Scanner 160A. They have a 160B out now but the 160A works just as good and a lot cheaper. We also use a 8508A for the meter.
Hey Nani Nani Cho Cho Cho, Hey Nani Nani Cho!

Hawaii596

#13
07-07-2011 -- 08:42:10
Hi PMEL,

I'm still just getting this whole thing up and running.  I hope to buy a Dataproof at some point.  For the moment, I want to get some trend analysis data to see which of my references has better or worse drift, so I can pick which to use or not use, which to be the main reference, etc.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
Lord Kelvin (1824-1907)
from lecture to the Institute of Civil Engineers, 3 May 1883

skidaddle skaduski

#14
07-15-2011 -- 11:56:37
Use VBA with agilent's I/O library.  I'm sure you already have excel, and wouldn't have to worry of tying up a metcal license.  What you are attemping is simple, and I use that word loosely, so I'm sure one of your guys can whip something up real quick and have it running in no time.
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