Przedsiębiorstwo Badawczo-Produkcyjne OPTEL Sp. z o.o. ul. Jerzego Kowalskiego 5 PL-52-428 Wrocław tel.: +48 (071) 329 68 53 fax.: +48 (071) 329 68 52 e-mail: [email protected] http://www.optel.pl Wrocław, 2020-10-26 Miniature ultrasonic data acquisition system with integrated 2-channel pulser&receivers Valid for hardware with firmware: Rev. 2.2.80 Document version: Date of creation:

3. Starting the work with the device OPBOX-2.1 is powered from USB interface and is conform with USB2.0 standard. According to its requirements there are some limits, concerning power supply (max. start current, max. continuous power). To fulfill this standard requirements OPBOX 2.1 has three independent power supply branches (analogue part, 12V part and ADC/DAC converters part). Each branch has independent signals, switching it and showing error conditions. After connecting the device to the USB port, all three branches are switched off and only digital part, responsible for communication is...

Each measurement cycles creates in memory a data frame, where first 54 bytes are a header and remaining part is created by the signal data coming from the ADC; The header contains actual information about the given measurement, such as: measurement index, encoder position in the moment of trigger, the results of hardware peak and transition detectors, etc. The settings of signal acquisition mechanism allow to adapt flexible buffering according to actual needs of application and hardware possibilities with the goal to reach the required measurement speed in the real time. The acquisition mode...

Elements defined above are shown on the following picture. Figure 5.1: Data organization in Header and Packets Header

7. Configuration and maintenance of acquisition in real time Configuration and maintenance of acquisition in real time should be made according to the following schematic: 1. Stop of acquisition, that is going on: blocking all trigger sources (bit TriggerEnable in TRIGGER register). 2. Setting of acquisition parameters: - Sender configuration - loading time and voltage level (register PULSE_TIME and PULSE_AMPLITUDE); - Analogue channel configuration - choice of input, attenuator, low and high pass filters, amplification (register ANALOG_CTRL, MEASURE, CONST_GAIN); - configuration of signal acquisition...

- receiving all packets until the moment as the flag PACKET_READY will have zero value. - the device buffer can contain a fragmentary acquisition packet (not the whole PACKET_LEN), the amount of remaining frames should be read from the register FRAME_CNT; - if FRAME_CNT = 0 it means, that all frames was received and the reading was correctly finished. - if FRAME_CNT is not equal zero (i.e N) the setting PACKET_LEN should be changed to exactly the amount of frames, that is remaining in the buffer of the device (N should be written to the register PACKET_LEN). Only in this situation the change...

8. Comments to the acquisition settings. 8.1. Calculating maximal packet length Hardware acquisition buffer allows to store maximally 256kB samples (single measurement data – exactly 262144). Maximal value of packet length (PACKET_LEN), means the amount of full frames, that the device can store in internal memory depends on the length of measurement window (DEPTH) and can be calculated from following formulas: PACKET_LEN_MAX = INTEGER PART[262144 / FRAME_SIZE] = = INTEGER PART[262144 / (DEPTH + 54)] In the mode without writing measurement data (StoreDisabled): PACKET_LEN_MAX = INTEGER PART[262144...

8.3.1. Change of the measurement window setting (DEPTH) Changing of DEPTH setting causes that it is necessary to calculate new parameters of acquisition buffering (PACKET_LEN_MAX, placing of frames in relation to memory of TGC curve, etc.). Changing DEPTH parameter automatically changes the packet length too. For this reason each change of the length of measurement window (writing to DEPTH register) causes the reset of acquisition buffer. All acquisitions that are stored in the buffer are removed. To avoid the loss of data stored in the acquisition buffer it is recommended to change the DEPTH...

a) the acquisition in progress In this case the new acquisition will be not started, and trigger impulse will be counted by the module of lost triggers counter (TrgOverrun) and the bit TrgOvrScr_A in CAPT_REG will be set. The value of this counter is written to the acquisition header immediately after it is finished. This value shows the amount of triggers that was lost since the previous acquisition was finished – during the actual acquisition. b) the frequency of trigger pulses is larger than 10kHz (their period is smaller than 100µs) OPBOX-2.1 has internal module limiting maximal repetition...

Frame 3 Frame 2 HEADER_SIZE = 54 Figure 8.1: Organization of TGC curves in the Table of Amplification Curves The sending of amplification curves to the device should always include the transfer of the whole 256kB table of data, needed to write the whole TGC curves buffer. Partial writing of data to this buffer can cause wrong function of TGC function during some acquisitions and cause problem with following writing curves to the memory (shift of hardware data pointer, etc.). If necessary it is possible to make a reset of TGC curves controller using the commands FIFO_RESET (0xD2) or RESET (0xD1)....

9. Maintenance of Peak Detectors modules OPBOX 2.1 has three hardware peak and level detector modules – gates PDA, PDB i PDC. They have following parameters: – three independent gates with peak detectors and level comparators; – configurable start and stop point for each gate; – configurable level for level detector (comparator); – configurable function modes: „Level”, „Rising”, „Falling” and „Transition”; – information about the moment of level transition; – information about the position and level of maximal signal value in the gate. Gates PDA, PDB and PDC must be configured in a following...