SonixDAQ Quick Test

Overview
The section outlines the procedure to test the SonixDAQ for collecting synchronized data.

Hardware
The PCI card should be modified in order to send the proper output pulses to trigger the SonixDAQ, follow the instructions here.

Software 5.x
It should be noted that SonixDAQ is only an acquisition/receive module and has not control over the transmits. Thus, all the parameters that have any effect on the transmit sequence need to be set properly prior to data acquisition. The following figure shows the list of all the parameters and their category on the Sonix Exam (version 5.x) that need to be adjusted prior to the data collection.

The description of each parameter is provided below:
 * In Category B-TX
 * Set “TX Aperture Max” to 64: Transmit with all the elements. Note that this number is half aperture. Thus setting it to 64 will result in aperture size of 128.
 * Set “Pulse Repeat” to 1: Transmit only one pulse. This pulse is defined by “pulse index”. For example if pulse index is 0 i.e. +- setting “Pulse Repeat” to 4 will change the transmit pulse to +-+-+-+-.
 * Set “Plane Wave” to 1: Centers the aperture and sets all the transmit time delays to zero to generate unfocused plane wave transmits. If this parameter is set to zero the aperture center will move across the image similar to standard imaging. Also focusing time delays will be applied to all transmits.


 * In Category B-GEOM
 * Set “Line Density” to 128: Force the exam to work with true elements instead of virtual elements.


 * In Category SYNC
 * Set “Trigger Out A” to 1: Sends Synchronization signal to the BNC cable for the DAQ where 1 means one trigger after each transmit, 2 means one trigger after each frame i.e. after every 128 transmits.
 * Set “Trigger Out B” to 3: Sends 40MHz Clock signal to the other BNC cable that can be used by the DAQ. Note that this step is optional and the DAQ can use its own internal clock. If you prefer to use the internal clock set this parameter to 0 and also in the DAQ SDK set the “clock configuration” to be internal.


 * In Category DAQ
 * Set “Open Connector” to 3: Opens the third connector on the SonixTouch so that the DAQ can listen and capture the echo signals as well as the probe itself.
 * Set “DAQ Output” to 1 (Writes the DAQ parameters into a file so that DAQSDK can use them. Note that this is optional. In case the user wants to enter the parameters manually this parameter does not need to be adjusted.


 * In Category TX Aperture Curve
 * Make the curve flat so that at the beginning of the transmit, the full aperture is used.

Note: The parameters which are bold are important and have to be set for proper data collection. Other parameters are optional and can be changed/ignored depending on the application. For more information, please see the explanation for each individual parameter.

Software 3.x
The following section shows the list of all the parameters on the Sonix Exam (version 3.x) that need to be adjusted prior to the data collection.


 * Run the Exam software on the Sonix system. Switch to the standard B-mode imaging and enable the research mode.
 * Once the Exam software is running, on the left mouse-over menu adjust the following parameters:
 * Open Connector ->3 : This will open the 3rd connector (i.e. the last connector) so that the DAQ can see the signals from individual channels to the DAQ probe connector.
 * Output Sync ->1 : This will activate the output synchronization signal on the Sonix's BNC connector. The DAQ will use this signal as a trigger to start the acquisition after each transmit.
 * Focus Count -> 1: This will make sure only one transmit is used for each scan line/channel acquisition.
 * Write DAQ -> 1 : This will force the Sonix Exam to write the DAQ parameters (i.e. line duration, number of samples, and receive delay) into a binary file (D:\daq-b.prm). This file can then be used in the DAQ software to load data acquisition parameters automatically. This step is optional and the parameters can also be entered manually in the DAQ software.

It is important to note that the signal will be the same for both the probe connector and DAQ probe connector. The DAQ will capture the channel data in a parallel form without affecting the signal in the probe connector. Thus the standard imaging process remains untouched during channel data acquisition.



Testing the BNC Output
Connect the output of the Sonix's BNC connector to an oscilloscope and make sure the synchronization signal is working properly. The output has to have 5 volt amplitude and 50 ns duty cycle. The frequency of the synchronization pulse is determined by the Sonix system. In case of using Line Trigger (Output Sync ->1), the frequency should be around 10kHz and in case of using Frame Trigger (Output Sync ->2), the frequency should be around 100Hz. Once you the sync signal passed the test, disconnect it from the oscilloscope and connect it to the DAQ.



Preparing the SonixDAQ

 * Make sure your DAQ is properly connected and the power is on (please see the DAQ hardware Section for this).
 * Run the DAQ software and press "Create Sequence ..." to initialize the DAQ.




 * Once DAQ is initialized and the FPGAs on the DAQ are programmed, the "Sequencer Window" shows up as shown below.
 * Select Load From File. This option will only work if you have previously set the Exam software to save the DAQ parameters (i.e. SaveDaqParam ->1 in the Exam software). Alternatively you can enter the parameters manually.
 * Select all the channels.
 * Set the Start Configuration to external. This will force the DAQ to wait for the trigger signal before starting the data acquisition. For this mode to work properly the trigger signal should be available (i.e. Sync Out ->1 in the Exam Software).
 * Set the DDR2 Size to be 8MB (instead of 4GB). This will significantly reduce the time required to transfer the data from the DAQ back to the PC.
 * Press the Start Sequencing. If the test works fine the buffer will be filled with data very soon an you will see All RX buffers have been filled message in the Status box, other wise you will see RX buffer 1 is not full yet.

Note: make sure the Exam software is running and it is not in the freeze mode. If the Exam is frozen it will not send any sync signal to the DAQ. As a results DAQ will not collect any data and the message RX buffer 1 is not full yet will be shown in the Status box.


 * Once data are acquired, transfer/save the data by pressing Download Data.
 * Once data are downloaded, look at the results using the Main window in the DAQ software (please see the DAQ software Section for this). Alternatively, provided Matlab subroutines can be used to load the channel data.