Reading The Min & Max Settings for a channel in Labview

[MikeW1973]

Hi All,

I am creating a channel calibration routine in Labview and its all going pretty well, apart from returning the channel Min and Max values. I need these when i add scales and need them to be written back with the scale amplification.

1102 Voltage and 1121 Voltage read back fine as -5 +5 and -10 +10 , I then had a problem with the resistance Min Max on the 1102 card as always return -1 and +1 for these values. I have since found out i can calculate these by dividing 1 by the Excitation Value and then multiplying by 10.

However I am now onto the 1102 Thermocouple channel set up and it just keeps returning -180 for the min and 186 for the max, Yet when i have the channel configured for say a K type thermocouple in units degC in the measurement and automation software it allows -210 to 1200 whch is correct. Anyone know why its not returning correctly or if there is an easy calc to work them out like on the resistance channel.

One other thing, i also notice that there is no custom scale setting in the measurement and automation software for Thermocouples yet i can write scales away for it from labview - must be a bug i presume in the measurement and automation software ?

Thanks for any help

I use the Daqmx property node to read back the min and max values , im on labview 8.2  and installed nidaqmx8.3 for the measurement and automation sofware etc

Mike

[Kurt_NISalesEngineer]

Hi,

Thanks for posting your query on the National Instruments discussion forums.

I’m hoping you can go to Measurement and Automation Explorer and do a file > export to save your MAX configuration to an .iak file that you can attach to this discussion forum so that I can take a closer look at the task that you have created in MAX. Would it also be possible for you to attach your VI to the discussion forum so that I can get a clearer picture of what you are attempting? Am I correct in assuming that you working with native low level NI DAQ VI’s or NI DAQmx VI’s on the block diagram? What DAQ card do you have in your machine?

I’m wondering if you have tried to create custom scales by right clicking on the Scales directory in the configuration tree in MAX (under historical data directory and above Software directory).

I look forward to your reply!

Kind Regards,

Kirtesh Mistry

Applications Engineer

National Instruments UK & Ireland.