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DAC161S997EVM: DAC161S997EVM : how to start for reading SPI sensor to 4-20ma

Part Number: DAC161S997EVM
Other Parts Discussed in Thread: DAC161S997, , ADS1220

Hello every one

I am new here. 

Could you please suggest us how to start for reading SPI sensor to 4-20ma?

1. Can I use this DAC for reading SPI sensor to 4-20ma?

2. If 1. yes,  please suggest us how to start for reading SPI sensor to 4-20ma?

3. Please suggest Hardware tool and Software tool for this coding, if it's necessary?

4. I found that the SPI pin on this board, it also connect to IC DAC4-20 ma. Can I use this SPI pin for connecting my SPI sensor? Any are welcomes.

5. I suspect that why SC pin on IC DCA4-20ma always High. I've knew that normally it's "ACTIVE LOW" to detect SPIdata. Please suggest us.

Please help, any are welcome.

Best regards,

waseda

  • Waseda,


    I'm not entirely sure what you're asking, but I think maybe a diagram from the datasheet might answer your question.

    The DAC161S997 only does the 4-20mA current loop drive, it doesn't communicate with any sensors. From the diagram you can see that you need the microcontroller, to get data from the sensor (left side of the diagram) and then you use the microcontroller to send the data through the 4-20mA loop (right side of the diagram).

    If you are using the DAC161S997EVM, you can control the DAC161S997 through a USB cable connected to the computer. There is software that you can download from ti.com if you go to the DAC161S997EVM landing page. This software won't communicate with anything except this board, so you cannot use it to communicate with a sensor.

    You can find this at the following link:

    https://www.ti.com/tool/DAC161S997EVM#order-start-development

    Finally, we do have some reference designs as an example on how this might be put together. If you go to the following link, there is a design for an RTD temperature transmitter for 2 wire 4-20mA current loop systems. In that example an MSP430 is used as the microcontroller. It communicates with an ADS1220 that measures an RTD, and also to a DAC161S997 that then sends the signal to the 4-20mA loop.

    https://www.ti.com/tool/TIDA-00095

    Hopefully this will get you started. If you have any questions, please post back.


    Joseph Wu