TIDA-01486: Termination of transducer cable

Matthias Luzius

Part Number: TIDA-01486
Other Parts Discussed in Thread: EVM430-FR6047, , MSP430FR6047

Hello,

I want to use the EVM430-FR6047 an connect it to the TIDA-Board like discussed in this thread.

Later on i want to measure the flow with two clamp-on transducers on metal-pipes >= DN80. Do you have experiance to connect the transducers with a 50 Ohm Coax cable (RG 58/ 5m or 10m)?

What do I have to do with the resistors in the output-channel (Termination of the transmission line)? Do I have anything else to consider?

I tryed it with a 50 Ohm resistor in the output channel. This is the "best" result I`ve had so far, but unfortunately the result is useless.

Can you imagine the reason for this bad result?

Thanks for your help.

Best regards

Matthias Luzius

over 3 years ago

0 JohnFullilove over 3 years ago

TI__Expert 5120 points

Mattias, hello. Our Industrial Factory Automation team has been forwarded your question. Please allow us 1-2 business days to respond.

Best Regards,

J. Fullilove

Reference Design Operations

Texas Instruments

0 Giovanni Campanella over 3 years ago

TI__Intellectual 1560 points

Hi Matthias,

I cannot open the thread that you are referring at.

For the TIDA-01486 we used much shorter cable (~ 50cm). We have not tested with longer coax cables. How much is the impedance of your transducers?

Regarding the results you get, could you please help me to understand your system setup. Do you have already the TIDA-01486 connected to the MSP430FR6047 EVM? Which software and configuration parameters are you using?

In case the two boards are already connected, for the software please follow the recommendations at the end of this thread https://e2e.ti.com/support/microcontrollers/msp430/f/166/t/702532?tisearch=e2e-sitesearch&keymatch=tida-01486

For the configuration parameters look at fig.20 of the TIDA-01486 user guide:

https://www.ti.com/lit/ug/tidudo7/tidudo7.pdf?ts=1590958009586

Let me know if you need any further help.

Thanks

Gio

0 Matthias Luzius over 3 years ago in reply to Giovanni Campanella

Prodigy 60 points

Hi Gio,

yes, I already connected the Tida01486 to the EVM like discussed in this thread:

e2e.ti.com/.../904956

My Transducers have a impedance of 83 Ohms.

I'm using the original EVM example-software and set PD1, S1 and S3 to high. Because I'm using only one Pair of Transducers. In Z-Mode with the following Parameters:

Thanks

Matthias

0 Giovanni Campanella over 3 years ago in reply to Matthias Luzius

TI__Intellectual 1560 points

Hi Matthias,

I see you have set a 15.5 db gain. This might be too much for a DN80 and bring the receiving stage of the MSP430FR6047 into saturation. As you can read at the pag 21 of the TIDA-01486 user guide, we have set a 1.9 db gain for 10cm diameter pipe. Also we have changed the THVD3095 gain to 6 db for a total gain of 7.9 db which was more then enough to read back the signal.

What is your Vbias?

Thanks

Gio

0 Matthias Luzius over 3 years ago in reply to Giovanni Campanella

Prodigy 60 points

Hi Gio,

Did you use also clamp on Transducers or Inline? Can you tell me the type and manufacturer of these transducers?

What is your Vbias?

After a few more tests with my Transducers, I think that I have to increase the voltage above +15/-15V. I get the best results with maximum gain at +15/-15V. Because I want to measure also larger pipes I have to look for a more powerful High-Speed Amp. Can you tell me a suitable one? Lets say for +/- 50V ?

Thanks

Best regards

Matthias

0 Giovanni Campanella over 3 years ago in reply to Matthias Luzius

TI__Intellectual 1560 points

Hi Matthias,

We did the tests with 4 in line transducers.

Would this device fit in your application https://www.ti.com/product/OPA462?

Thanks

Gio

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TIDA-01486: Termination of transducer cable