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

Angel,

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

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.

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

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.

TDC1000_Config0                         41
TDC1000_Config1                         51
TDC1000_Config2                         04
TDC1000_Config3                         02
TDC1000_Config4                         00
TDC1000_TOF-1                           00
TDC1000_TOF-0                           00
TDC1000_Error_Flags                     00
TDC1000_Timeout                         00
TDC1000_Clock_Rate                      00
TDC1000_Conts_Trigger                   01
TDC7200_Config1                         00
TDC7200_Config2                         50
TDC7200_Interrupt_Status                00
TDC7200_Interrupt_Mask                  00
TDC7200_Coarse_Cntr_Ov_H                FF
TDC7200_Coarse_Cntr_Ov_L                FF
TDC7200_Clock_Cntr_Ov_H                 FF
TDC7200_Clock_Cntr_Ov_L                 FF
TDC7200_Clock_Cntr_Stop_Mask_H          00
TDC7200_Clock_Cntr_Stop_Mask_L          00
TRIGGER_UPDATE_FREQ                     0001
TDC_AVG/STDEV_NUM_ELEMS                 000A
SAVE_GRAPH_DATA_TO_FILE                 00
FLOW_MODE_SELECT                        00
Y-SCALE_CENTER                          0032
X-SCALE_RANGE                           0032
MEASURE_RTD1                            00
SAVE_RESULT_REGR_TO_FILE                00
GRAPH_MULTI_STOPS                       00
TDC_SELECT                              00
TEMP_RTD_SELECT                         00
TEMP_RTD_MODE                           01
TEMP_AVG/STDEV_NUM_ELEMS                000A
SAVE_TEMP_DATA                          00
GRAPH_YMAX_DATA                         0000000000014A62
GRAPH_YMIN_DATA                         00000000000149FE
TDC1000-HV_DRV_EN1                      00
TDC1000-HV_DRV_EN2                      00
HV_DRV_EN1_Period                       001E
HV_DRV_EN2_Period                       001E
ENABLE_POWER_CYCLE                      00
CLK_FREQ_(1-16MHz)                      8.000000
CLK_SOURCE_SEL                          00
CPU_CLK_FREQ                            05
CPU_CLK_EN                              00
TDC1000-HV_BST_PWR_EN                   00
HV_BST_PWR_EN_Period                    0000
FWD2REV_FLOW_DELAY                      0001
TDC1000-IMPE_MATCH_EN                   00
ENABLE_UART_STREAM                      00
ENABLE_MSP430TIMER_TDC                  00

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

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. 

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.