I am try to get a thermocouple by AD7124-4 application again.

Hello

I met AD7124 IC two years ago.

I knew great works well. I made 10 boards on same circuit as bellow.

when I turn on the board and check a coldjunction temperature(RT1), the 5 borads temperature is different.

the 5 boards are about 24 degree and the other boards are 30 degree. the part is used same.

what do i do wrong? 

my code is like this:

1) reset data send ( 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff)

2) channel-0 setting ( 0x09, 0x10, 0xA6)      // AINP=AIN5,     AINM= AIN6

3) config-0 setting ( 0x19, 0x01, 0xEF)      // unipolar, ref_bufp

4) filter-0 setting ( 0x21, 0xE6, 0x07, 0xFF)

5) IOUT setting (0x03, 0x00, 0x12, 0x0B)

6) when i read, (0x01, 0x01, 0x84); // ADC controll setting

                         (0x42, 0x00, 0x00, 0x00, 0x00) // read

 i send number 6) messages on period.

please, check my setting codes and help me.

thanks for reading.

  • Hi,

    You should have a look at our CN0391 thermocouple reference design which uses the AD7124. (http://www.analog.com/en/design-center/reference-designs/hardware-reference-design/circuits-from-the-lab/CN0391 )

    There is also some source code available on our ADI Github repository that you can take a look at and check your software settings with. (EVAL-ADICUP360/projects/ADuCM360_demo_cn0391 at master · analogdevicesinc/EVAL-ADICUP360 · GitHub  )

    Hope you find this helpful.

    Brandon

  • hello Brandon

    My circuit reference Analog Device CN0376.

    So I need EVAL source files for CN0376 board.

    Can you link the CPU cource files for CN0376 ? 

    I want to check SPI packet firstly.

    please link or send me..

    thank you for reading.

  • Hi Hahmin,

    I need to give you this disclaimer so that you understand the Analog Devices position on providing source code.

    Analog Devices doesn't support custom software development.  We provide the source code to you (the customer) as a service and tool to use to help jump start your design process.  Any issue that occurs during altering or editing the software will be your issue to debug and fix.  We will always refer you back to the working software executable should any issues arise.

    With that said, the source files for this application are LabVIEW files, and you will need the National Instruments program to open it.  You can download the zip file from this link ftp://ftp.analog.com/pub/cftl/CN0376/RevC/1.1.0/ 

    Brandon

  • Hi Brandon

    I understand your disclaimer about Analog Devices.

    A problem is that my english skill is poor. So I know misunderstand of 7124 datasheet.

    I just reference your software source codes.

    My problem is I cant control two channel operations.

    I use the NTC for coldjunction temperature and Thermocouple for Hot point temperature. So I have to use two channels of 7124-4 IC.

    I just want to how to channel settings for two resources through your C language source codes.

    There is no sources in the link.

    can you show me how to send the packet in the CN0376 devices?

    I am using the 7124-4 like this flow on my code:

    RESET for 7124-4

    setting for NTC at channel-0

    data reading for NTC

    after 1 sec

    RESET for 7124-4

    setting for Thermocouple at channel-0

    data reading for Thermocouple

    go back to first step.

    But I want to that like this flow:

    RESET for 7124-4

    setting for NTC at channel-0

    setting for Thermocouple at channel-1

    data reading for NTC

    data reading for Thermocouple

    data reading for NTC

    data reading for Thermocouple

    data reading for NTC

    data reading for Thermocouple

    My thermocouple setting is not right, so thermocouple data is not useful..

    1st question:

    If there is ADICUP360 codes for CN0376 devices, share for me. I will just check the packet for NTC and Thermocouple.

     

    2nd question:

    Is it ok when I reset the 7124-4 IC frequently ? actually, I cant set two channels, I do reset operation for channel-0.

    thank you for reading. thank you very much.

  • Hi Hahmin,

    As mentioned previously, there is no direct ADICUP360 code for the CN0376.  The CN0376 uses the AD7124 for the ADC.  We do have C code for the ADICUP360 for another thermocouple project using the AD7124.  That can be found here. (EVAL-ADICUP360/projects/ADuCM360_demo_cn0391 at master · analogdevicesinc/EVAL-ADICUP360 · GitHub ) 

    It won't be exactly the same as the CN0376, but it should show you how to configure things.

    Brandon