set up pressure transducers with 9203 module

[lkdfjaio1241]

I am new to DAQ. I am using an omega pressure transducer, PX209-30V45GI which produces a 2-20mA output(http://www.omega.com/ppt/pptsc.asp?ref=PX209_PX219) and a 9203 NI module. I have used the DAQ assistant but havent had much luck. I know the range should be linear and given that I can read ranges from -15 to 45 psig, the linear function that I believe should display the appropriate reading would be y=3.75x-30. This function give me -15 when 4 mA is produced and 45 when 20 mA is produced. However I can not even get past the DAQ setup. It tells me there is an error. Am I on the right path? Could anyone help me out with setting up this pressure transducer? I did notice that the 9203 module does have a + - 20mA where the transducer has 4-20 mA. May this be my problem?

Thanks in advance

[AdnanZ]

Well, what's the error you are getting? Is it possible to post a screenshot? The 9203 has ±20 mA and 0 to 20 mA programmable input ranges, so you should write in 0 and 20 for min and max to take advantage of better resolution. Have you setup a scale in DAQ Assistant yet? Have a look at some of the example programs to get a better understanding.

[lkdfjaio1241]

The error I am getting is Error-200077, requeseted value is not a supported value for this property. I can get a screen shot if this is not sufficient. Please let me know. I believe I have set up a scale, giving the scaling parameters of a slope of 3.75 and a Y-intercept of -30. Given the parameter of the output of the pressure transducer, an output of 4-20mA with a range of pressure values of -15 psig to 45 psig, a value of 4mA would give the low end, which is -15 psig and 20mA would give the high end which is 45 psig. Please correct me if I am wrong.

The 9203 does have a +- 20 mA programable input ranges, however I would believe that since my pressure transducer only has an output of 4mA to 20mA, I would want to write in those values as the max and mins. Again, correct me if I am wrong. Could you add some links to some example programs?

Thanks

Mitch 

[John_P1]

Hi Mitch,

The 9203 has both a unipolar and bipolar mode (0-20mA and -20-20mA respectively).  If you write 4 mA as the min value, the driver should coerce this down for you to 0 mA to meet the available ranges of the A/D converter.

Error -200077 should contain some additional information--specifically, it should include which value you are trying to set that is out of range.  If I had to guess, I would say it may likely be your max and min values, but the error message should give a good indication of where the problem lies.

-John