TDC-GP30 External circuit for gas meters Application Note.pdf-资料库

guizhou112115-12684944-4744300845407198796.pdf-第1页.png

第1页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第2页.png

第2页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第3页.png

第3页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第4页.png

第4页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第5页.png

第5页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第6页.png

第6页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第7页.png

第7页 / 共15页

guizhou112115-12684944-4744300845407198796.pdf-第8页.png

第8页 / 共15页

Application Note DN[Document ID] TDC-GP30 External circuit for gas meters ams Application Note [v1-01] 2017-Jan-31 Page 1 Document Feedback

TDC-GP30 in gas meters Content Guide 1 1.1 1.2 2 3 4 4.1 5 5.1 5.2 6 7 8 Introduction .......................................................................................................................... 3 Setup .................................................................................................................................... 3 The Parts of the System ...................................................................................................... 3 Quick Start ........................................................................................................................... 4 Installation of the Software ................................................................................................... 6 Circuit Design in Detail ......................................................................................................... 8 GPIO Signals ..................................................................................................................... 10 Hardware ............................................................................................................................ 11 Layout ................................................................................................................................ 11 Schematics ......................................................................................................................... 12 Contact Information ............................................................................................................ 13 Copyrights & Disclaimer ..................................................................................................... 14 Revision Information .......................................................................................................... 15 ams Application Note [v1-01] 2017-Jan-31 Page 2 Document Feedback

TDC-GP30 in gas meters 1 Introduction TDC-GP30Y is an ultrasonic flow converter (UFC) mainly for ultrasonic heat and water meters. However, the TDC-GP30 can cooperate with external analog switches and an amplifier for operation in other ultrasonic applications like clamp-on or gas flow meters. In this so-called gas meter mode the chip uses the available GPIO pins to drive external analog switches with higher voltages. An external amplifier in the receive path can be added, too. In the following we describe such an external circuit in combination with the GP30-EVA-KIT. 1.1 Setup The figure below shows the general setup of the system. Figure 1: General Setup The gray colored unit is the external test board GP30Y – Gasmeter V1.1 which drives the ultrasonic transducers for gas flow measuring applications. PicoProg and GP30-EVA-MODULE are the standard products of ams. 1.2 The Parts of the System The following table shows the parts required for the system. Figure 2: Elements of the test setup A) GP30Y Evaluation Board B) PicoProg V3.0 C) GP30Y Gasmeter V1.1 ams Application Note [v1-01] 2017-Jan-31 Page 3 Document Feedback USBPCPICOPROGV3.0GP30-EVA-MODULEGP30-Gas meter test boardGas spool piece and transducers

TDC-GP30 in gas meters 2 Quick Start 1 First thing to do should be the installation of the system. Therefore, please first plug the Gasmeter V1.1 on to the GP30-EVA-MODULE as it is shown in the figure below. Figure 3: Connection of the Gasmeter V1.1 with the EVA-MODULE 2 Connect the PicoProg V3.0 (or V2.0, if you have an old one) to the EVA-MODULE. For the moment do not connect the USB cable to the PC. Figure 4: Connect PICOPROG 3 Now install of the ams GP30 evaluation software. For details see chapter 3. If the software and PicoProg driver is already installed then you can skip this section and continue with item 4. 4 Start the software and connect the PicoProg and the PC by means of the USB cable. 5 Click on System Reset button. The two indicators on the GIU, namely Pico Prog FW Version and Comm. With GP30 OK? should now turn to green. 6 The next step is loading the configuration file and writing it to the GP30. Therefore, go to File ► Open Config Search for the specific configuration file for gas meter applications: ams Application Note [v1-01] 2017-Jan-31 Page 4 Document Feedback

TDC-GP30 in gas meters GP30y_config_GasMeter_[Project Name].cfg Caution! Never use configuration files other than for gas meters, as long as the gas meter board is plugged and energized by external voltage. 7 Click on the Write Config button to write the configuration file into the TDC-GP30 chip. 8 Connect the external voltage source (9 to 20 V) and the transducers (spool piece) to the Gasmeter V1.1. Please refer to the figure below. You can now energize the Gasmeter V1.1 with an external DC voltage which will define the peak voltage of the ultrasonic fire pulses. Caution! The maximum external dc voltage that the board can bear is 20V. However, the maximum ratings of the transducers should also be taken into account. Figure 5: Connection of the transducers and power supply External DC voltage connection Spool piece connection The cable connection of the transducers for test purposes is shown, too. 9 Click on Start Measurement button to start the measurement process. After this step, the chip should start measurement and the results should be seen at the software. For the graphical demonstration of the results please open the graph view by clicking on Open TOF Graph. ams Application Note [v1-01] 2017-Jan-31 Page 5 Document Feedback

TDC-GP30 in gas meters 3 Installation of the Software There is a set of files required for installation of the PicoProg and the GUI (Graphical User Interface) of the development kit. The file structure is shown below and the steps to do the installation follow. 1 Open the directory (version 1.5.2 or newer) and the Volume directory inside. Run Setup.exe (installer). Now select the installation path, recommended is the default setting. Then click to “Next” and confirm the license agreement. After that, a window appears that shows a summary of the software (includes the PicoProg driver) to be installed. This part of the installation can take some minutes to complete. 2 Restart the computer. 3 Set up the hardware connections as previously explained. Then connect the USB cable to the PC (figure 6). So that the USB device (PicoProg v2.0) is installed on a Windows PC. Double check that the shows up as a functioning USB device in the Windows Device Manager similar to this, Figure 6: Connect PICOPROG and PC Only in case it is not showing up or not properly installed, please run the PicoProg Driver Installer. To do so, navigate to and run Setup.exe (installer). You will need to hit Next a few times to complete the installation. 4 Run the GUI software by clicking on . You may be prompted for a GP30 Evaluation License Code to unlock the software. If so, please send an email request to support.stutensee@ams.com to request an unlock code with validity for one year. Enter the code provided into the dialog box and the software will unlock. ams Application Note [v1-01] 2017-Jan-31 Page 6 Document Feedback

TDC-GP30 in gas meters Figure 7: Graphical user’s interface (GUI) of the GP30 evaluation software. 5 Click on System Reset button. The two indicators on the GIU, namely Pico Prog FW Version and Comm. With GP30 OK? should now turn to green. First one indicates that there is communication between the computer and the PicoProg. The second indicator verifies if the communication is working to the GP30-EVA-MODULE. ams Application Note [v1-01] 2017-Jan-31 Page 7 Document Feedback

TDC-GP30 in gas meters 4 Circuit Design in Detail The circuit design and the layout of the Gasmeter V1.1 can be seen in section 5. Basically, the Gasmeter V1.1 is designed to send ultrasonic fire pulses that have relatively high peak values and amplify the received signal to a value which is meaningful for the GP30. The circuit was designed for development and test purposes, therefore there are many things added to increase the flexibility, observability and immunity against other disturbances. May be the number of devices used is also not quite as less as it could be. For instance the quantity of some analog switches, e.g. U2 and U17, could be decreased to one, or instead of separate housing 2 switches at one device could be used… However to decrease crosstalks and increase the robustness such savings haven’t been done. In the circuit the jumpers can be seen almost everywhere (J19, J20, J21, etc.). This was done for the sake of flexibility. Because it makes it quite easy to separate certain parts from the whole circuit and see its advantages/disadvantages to the system. Moreover, the circuit has been equipped with some test points. So that it is easily observed what is actually going on in that certain point of the circuit. On J5 and J6 the sent signal or the received signal before the amplification can be seen. The amplified received signal can also be seen on J31. The circuit is coming with a default assembly of 560 Ohm resistors in the driver/Receiver patch. For transducers with different impedance resistors R1, R5 and R6 need to be matched to the transducer. Figure 8: Resistors to adopt to transducer’s impedance The figure below was taken from the oscilloscope while the GP30 was performing zero flow measurement. The oscilloscope was triggered by the signal on J5 and the amplified received signal was seen on J31. The fire pulses (yellow signal) have 13Vpp values while the received signal on the transducer is only around 20mVpp. Without amplification this value is just senseless and impossible to be detect by GP30. Therefore an external amplification unit has been used on the circuit which also be controlled by the GP30. After opamp, the received packet reaches to 500mVpp. ams Application Note [v1-01] 2017-Jan-31 Page 8 Document Feedback

资料库

TDC-GP30 External circuit for gas meters Application Note.pdf

相关推荐

行业

热门标签

最新资料