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TDC1000-C2000EVM: TDC1000-C2000EVM MODES OF OPERATION AND TRANSDUCER SELECTION

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Part Number: TDC1000-C2000EVM

Our interest is to find the differential time of fight (ToF) between two Ultrasonic Transducers placed apart at 10cm in Air/water medium. One of our clients gave two pair of sensors (Bina-1G2-1035 Ultrasonic transducer with Center frequency:975 ±30KHz & PSC1.0M02 2300 H2AD 4 B0 Ultrasonic flow sensor with nominal frequency 1.0±0.1MHz from ZHEJIANG JIAKANG ELECTRONICS CO., LTD.)for this ultrasonic application. We connected one of the wires of the Bina-1G2-1035 Ultrasonic transducer with the TDC1000-C2000 EVM at TX1 and another at GND in J5 connector. We didnt get corresponding changes in TDC avg window when the distance of the transducer is doubled. We are getting values around 37 micro second.

We need your support on the following: (i)Two Ultrasonic Transducers connection for Mode0, Mode1 and Mode 2 to find differential ToF and the corresponding settings required in the TDC1000 tab (ii)List of sensors that are compatible with this EVM and sensor specifications such as excitation frequency, excitation source voltage, Distance between the transducers, Resonance impedance and static capacitance.

  • Angel,

    I have received your question and I will get back with you by Wednesday.

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to Bharat Aravamudhan:

    Thank you! Awaiting the answers for the queries.

  • Angel,

    I understand that you plan to place 2 transducer facing each other and plan to measure the ToF.

    Now, Mode 0 is intended for Level and Fluid Identification Measurements applications. The TDC1000 associates each transducer to complementary TX and RX channels. The transmit/receive pair “TX1/RX2” will act as both transmitter and receiver for a measurement if CH_SEL = 0 in the CONFIG_2 register. The transmit/receive pair “TX2/RX1” will act as both transmitter and receiver for the measurement if CH_SEL = 1. The TDC1000 performs a single TOF measurement after receiving a trigger signal and returns to the SLEEP mode when the measurement is complete.

    In Mode 1 the TDC1000 associates each transducer to a single TX and RX channels. The transmit/receive pair "TX1/RX1" will act as both transmitter and receiver for a measurement if CH_SEL = 0. The transmit/receive pair "TX2/RX2" will act as both transmitter and receiver for the measurement if CH_SEL = 1. The TDC1000 performs a single TOF measurement (one direction) and returns to the SLEEP mode when the measurement is complete.

    Mode 2 is intended for transit time water flow metering applications (see Water Flow Metering). In this mode, the channel definitions are the same as for Mode 1: Channel 1 = "TX1/RX1" and Channel 2 = "TX2/RX2". The TDC1000 will perform one TOF measurement and go into READY state waiting for the next trigger signal. Mode 2 supports averaging cycles and automatic channel swap

    Also we recommend using 1Mhz transducer to measure ToF through liquid and lower frequencies say 30Khz to 200Khz for measuring ToF through air medium.

    For water application, we recommend STEMiNC’s 1-Mhz transducer (p/n SMD10T2R111) & For air application, we recommend Murata’s 40kHz transducer (p/n MA40H1S-R) or ProWave’s 40 kHz transducer (p/n 400PT160). 

    Please let us know the particular application for us to provide you with correct setting for the same.

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to Bharat Aravamudhan:

    Hi Bharat Aravamudhan,

    Thanks alot for the information. Our client disclosed that the application is of water medium. We connected two Bina-1G2-1035 Ultrasonic transducers with Center frequency:975±30KHz at RX1 and TX2, TX1 and RX2, TX1 and TX2, RX1 and RX2 for mode 2 , ie, tried different combinations. But we didnt get any graph in the GUI. We tried to analyze waveforms of START BUFFER, STOP BUFFER, VCOM BUFFER, COMPIN BUFFER using DSO. We got accurate System clock waveform of 8MHz. For VCOM BUFFER and COMPIN BUFFER, we got a low to high pulse, and for START BUFFER, we didnt get any wave, but we got a stop pulse. Please help us on the Mode2 operation settings to get TOF. Since you mentioned that  each transducer for mode 1&2 will act either as transmitter or receiver, Do we need to remove zero ohms R81 and R81 as they are connecting TX2/RX1 and TX1/RX2? Please refer the settings attached in the doc and advise on the same . The values in the TDC1000 tab are not reflecting in the DEBUG page of GUI, please clarify.SCREENSHOTS OF EVM GUI SETTINGS.docx

  • In reply to Angel James:

    Angel,

    For Mode 2 please remove the zero ohms resistors R80 & R81. Also we recommend the MSP430 based device for the liquid flow meter for better accuracy.

    http://www.ti.com/tool/MSP-ULTRASONIC-DESIGN-CENTER

    Please provide me more info on the exact application from your end. 

    I have attached a register map to measure liquid level sensing in a setup which is in a plastic container.

    Please provide me a screenshot of the START, STOP, VCOM , COMPIN pins in your application.

    TDC7200_Setup-Water Cube Mode0-4Avg.txt

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to Bharat Aravamudhan:

    Hi Bharat,

    I have tried for Mode2 operation by removing zero ohms resistor R80 & R81 before itself. But I didnt get any graph on the GUI. Today I have tried by loading the settings you have given. Since it is for liquid level sensing, I used Mode0 setting. I got some popup saying "The input string does not contain data in the expected format". I got TOF around 29 micro seconds. But then when i changed the distance between the transducers I got the same result. I have attached screenshots related to this instance.

    Since our interest is to find the time of flight, We need to work on Mode2 operation settings. So kindly assist us on the Mode2 operation. I have attached the screenshots of  GUI settings, graph and debug page and waveforms of START, STOP, VCOM, COMPIN pins in the document format. As soon as our client discloses about the exact application, we will let you know about it.

    Thanks!Mode0 after loading TI settings.docxMODE2 SETTINGS & WAVEFORMS.docx

  • In reply to Angel James:

    Angel,

    Please provide me the setup that the customer is trying, Mode 0 is used for short time of flight application more for level sensing and concentration determination. While Mode 2 is for liquid flow and for accurate liquid flow measurement please use the MSP430 based flow meter device. 

    I will need the setup container sizes and orientation of the transducers to help in this debug.

    The TDC1000 tends to provide erroneous reading in flow measurement especially when there is no flow. 

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications

  • In reply to Bharat Aravamudhan:

    Hi Bharath,

    Today, we have tested TDC1000-C2000 EVM using New Transducer which is recommended in the appnote  SNAA266A by immersing in the water medium by loading the settings given by Mr. Selva Kumaran (selva@ti.com) from TI team for mode 2 operation and also he supported us over call and WebEx. We got expected results in our Phase 1  testing.

    Thank You TI team for unwavering support!! Hope we will get the support in our next level of testings too. 

  • In reply to Angel James:

    Angel,

    Glad that we were able to help you with this testing. 

    Please feel free to ask any question in the e2e forum in future.

    ---------------------------------

    Bharat Aravamudhan

    Sensor Signal Conditioning Applications