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TDC1000-TDC7200EVM: Control two Transducers in ultrasonic level measurement

Nabila cherifi
Prodigy 40 points

Part Number: TDC1000-TDC7200EVM

Hey,

I'm working with the board TDC1000 & TDC7200 EVM. I use this EVM with a PZT transducer of 3.4 MHz and a reflector to get the concentration of my fluid using the ToF measured and it works perfectly. Knowing that the RX1/TX2 are connected between them. But now i want to use two PZTs one as emitteur and the other one as receiver. I didn't find any documents about how to use two transducers in fluid concentration measurement. So my questions are :

1- Is it possible to use two transducers of 1 MHz up to 3.4 MHz in fluid concentration measurement using this EVM? the distance between the PZTs is 35 mm.

2- What are the configurations that i should do to have a transducer as a receiver only and the other as transmitter?

3- If we can't do this with this board, can i use the TDC1000 gasEVM instead of the first one? how?

Please i need you're help as soon as possible. Thank you

  • 0
    TI__Mastermind 31655 points

    Hello,

    Yes, it can be used in this way. You will need to set the measurement mode to 1. The datasheet describes the measurement modes here:

  • 0 in reply to Scott Cummins
    Prodigy 40 points
    Hi Scot,

    Thanks for your answer.

    so if i understand clearly, when I configure to mode 1 and choose CH_SEL to 0 i will have : transducer A which is connected to pin 8 (TX1) of the EVM, it will work as receiver. The transducer B which is connected to pin 12 (RX1) of the EVM, it will work as transmitter.
    is it okey?

    The ToF that i will get from the GUI is it the one for a one way wave or I have to calculate it from the oscilloscope?

    thank you :)
  • 0 in reply to Nabila cherifi
    TI__Mastermind 31655 points
    Hello,

    If CH_SEL is 0, TX1 will be the transmitter, and RX1 will be the receiver.

    The TOF you see from the GUI will be the time from when the TX starts to when the RX receives the signal, so it will be one way.

    Regards,
  • 0 in reply to Scott Cummins
    Prodigy 40 points

    Hi scot,

    thanks a lot for your answers, i followed all what you've said and all works as i want :)

    but now i have some questions : 

    -What is the impact of the number of pulses in the two configurations : Transducer A and transducer B with a distance of 39mm, Transducer A with a reflector ? the frequencies are in range of 1MHz up to 4MHz.

    -How to choose the right value of threshold voltage? and what is it's influence ?

    -If i want to increase the amplitude of my received echos, is it better to excite more the transducer? if yes, how to do that externally knowing that with this *tdc1000 EVM" the maximum voltage is up 3,5V i guess?

                                                                                              , or by amplifying the received signal? if yes how can i do that?

    -I've seen that by using one transducer we have to pay attention on which distance we use cause we've the ringing. It can influences the returned echo, which means have a false value. So how to reduce that without changing the distance we use?

    -i didn't found more information on the Auto Zero Period, So what is really its role and impact on the measurement of time of flight?

    If my questions are not too clear just let me know :) 

    Really a great thanks

    Nabila