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ADS122C04EVM: Can not load register map automatically after installation

Part Number: ADS122C04EVM
Other Parts Discussed in Thread: ADS112C04EVM, , ADS122C04, ADS112C04

Hi TI,

I found for my case, after following the procedure of installing "DELTASIGMAEVAL-GUI-installer" & "ADS122C04-dvcpkg", my console shows Hardware connected. Ready...., but not showing the corresponding register.

after some study, I think it's because the register map is not successfully loaded or installed? I tried re-installed few times but it's not helping. Could anyone give me some advice on solving this?

Thanks,

Tim

  • Hi Tim,

    It would appear that the device package was downloaded but was not actually executed.  Make sure that you actually run the ADS122C04-dvcpkg.exe.  This will place the files for the EVM in the Documents folder similar to as shown below:

    Also make sure that the device package matches the EVM being used.  The ADS122C04EVM and ADS112C04EVM look very similar but use different device packages.  So make sure that you are using the correct device package for the EVM you are using.

    Best regards,

    Bob B

  • Hi Bob,

    Thanks for your reply. 

    After checked, I did get a ADS112C04 EVM instead of ADS122C04, after install the corresponding exe, the register map works fine.

    However, I am not quite sure my following steps are correct for a K type thermocouple measurement cause I am not getting any reading.

    I connected the EVB with jumper setting as below and insert the two pins of thermocouple to JP6(I tried all the combinations), and click data analysis and press collect data, but nothing came out. Wondering if I got any setting wrong?

    Thanks for the help,

    Tim

  • Hi Tim,

    Check your configuration settings.  The default setting for the ADS112C04 is a data rate of 20sps and the data collection is for 2048 samples.  This means that the collection time is over 102 seconds.  So you may not be patient enough.  Change your collection to something more reasonable like 128 samples, or increase your data rate to something much faster.

    Also, only click the Collect Data button one time.  Repeated pressing of the button may lock up the GUI so that it becomes unresponsive. If data is being collected you should also see a flashing LED on the EVM that flashes approximately once a second.

    Best regards,

    Bob B

  • Hi Bob,

    Thanks for your information, after I changed the sample size, the reading did come out. However the reading seems to be weird to me.

    Since there's no too much info about how to set up a T-type thermocouple sense configuration, could you help check if following setting is correct?

    Thank you,

    Tim

  • Hi Tim,

    Take a look at the ADS112C04EVM user's guide and in particular sections 5.1 (page23) and 5.1.2.  The EVM is designed to connect a thermocouple to the AIN1 and AIN2 inputs.  So using AIN3 would not be the appropriate connection for a thermocouple input.  Instead following the configuration shown for a thermocouple input in Table 10.

    Based on the second screen shot it appears that you want to use the internal temperature sensor of the ADS112C04.  Although you can use the ADS112C04 temperature sensor, the EVM was not designed to use this sensor as the ADS112C04 is not directly connected to the isothermal area of the connector.  So using this method will not be be as accurate as the method described in the user's guide.

    To determine the thermocouple temperature you need to take two measurements.  The first measurement is the voltage measured by the ADC for the thermocouple.  The second measurement is the temperature measured by the ADS112C04 internal temperature sensor.  You will need to convert the temperature to a voltage for the 'T' type thermocouple (like from a table) and then add the ADC measured voltage to the voltage converted from the temperature sensor.  Lastly you will need to convert the total voltage back to a temperature.  This is a manual operation and the GUI cannot do these calculations for you unfortunately.

    Best regards,

    Bob B

  • Hi Bob,

    Thanks for the clear guidance and information, the reading becomes more reasonable to me, but it varies in a relatively large scale, I guess it's the connecting problem between my thermocouple and the connector on EVM.

    One more ask if I may, can you help me double confirm the following reserved design is feasible for a T-type temp sense case? Basically we followed the design in the EVM guide and datasheet, but it will still make me feel much relieved if the design is checked by TI's expert like you. Thanks a lot!

    Regards,

    Tim

  • Hi Tim,

    This is the basic thermocouple input circuit which would apply to all thermocouples such J, K, S, T, etc..  Where many customers run into issues is with the cold-junction measurement.  What is ideal is the connector be placed in an thermally isolated region and the temperature measured precisely at the connector.  So as long as you can accurately measure the temperature at the cold-junction you should be fine.

    Where some customers have issues is when the cold-junction temperature monitor is too far from the input connector.  This can cause a variation in the temperature reading causing an error in the cold-junction measurement.  This error when combined with the ADC measurement can produce an error in the overall temperature result.

    Best regards,

    Bob B