sysjoint V3 Portable Vector Network Analyzer User Guide

NanoVNA-F V3
Portable Vector Network Analyzer
User Guide
Rev. 1.0
(For firmware V0.5.0)
SYSJOINT Information Technology Co., Ltd.

Introduction

1.1. About NanoVNA-F V3
NanoVNA-F V3 is a Portable Vector Network Analyzer (VNA) with frequency range of 1MH z ~ 6GHz. It can be used for S11 and S21 measurements. The S21 dynamic range of NanoVNAF V3 is 65 dB, while the S11 dynamic range is 50 dB.
NanoVNA-F V3 is suitable for antenna testing of MF/HF/VHF/UHF/SHF bands, such as shortwave antennas, ISM band antennas, WiFi antennas, Bluetooth antennas, GPS antennas, etc.
It can also be used to measure filters, amplifiers, attenuators, cables, power dividers, couplers, duplexers and other RF components. NanoVNA-F V3 supports a variety of display formats: Log Mag, Linear Mag, Phase, Smith R+jX, Smith R+L/C, VSWR, Polar, Group delay, Resistance, React ance, etc. In addition, NanoVNA-F V3 supports TDR function which is useful for cable lengths measurement.
NanoVNA-F V3 is designed with metal case, which is durable and can effectively shield electromagnetic interference. The dimension of NanoVNA-F V3 is 125mmx75mmx20mm. The RF interface of NanoVNA-F V3 is SMA connector witch can be used to connect DUTs directly.
With the optimally designed signal processing system, the scan speed of NanoVNA-F V3 is up to 200 points/s and the maximum scanning points is up to 801.
The screen of NanoVNA-F V3 is a 4.3-inch high-brightness IPS with resistive panel, which allows users to see the screen contents clearly in outdoor. NanoVNA-F V3 adopts a full touch screen design, with 3 physical buttons, users can quickly set frequency range, scale, turn on/off traces, add/delete markers, and so on. The operation is quite convenient and smooth.
The NanoVNA-V3 has 4500mAh lithium-ion batteries with a battery life of up to 5 hours. The charging interface is USB Type-C, and the Type-C cable can be used to charge the device and also for data transfer.

1.2. FEATURES

• Frequency range：1MHz – 6GHz;
• S21 dynamic range：65dB，S11 dynamic range：50dB;
• 4.3-inch high-brightness IPS display with resistive touch panel；
• Metal case, effectively shield electromagnetic interference;
• SMA connector, stable and durable;
• Full touch screen and 3 physical buttons, convenient and smooth operation;
• Dimensions: 125mmx75mmx20mm;
• Built-in 4500mAh lithium-ion batteries with a battery life of up to 5 hours;
• TDR function, which can be used to measure cable length;
• Up to 4 reference traces;
• Up to 4 markers, and the marker table can be dragged to anywhere on the screen;
• 12 save/recall slots;
• Charging via USB Type-C, and the charging voltage is 5V DC;
• Designed with a 5V/1A USB power output port;
• Firmware upgrade via virtual U disk with USB Type-C cable;
• Comes with SMA calibration kit and 2 x 20cm SMA-JJ RG405 coaxial cable;
• Supports console commands commands and PC software;

1.3. Specifications

1.4. VNA basics
Vector Network Analyzer(VNA) is the most commonly used instrument in the field of RF and microwave, VNA measures the reflection and transmission behavior of a device under test (DUT）across a configured frequency range. VNA is usually used to measure antenna impedance, cable loss, filters, power splitters, couplers, duplexers, amplifiers, etc.
Note that the “network” mentioned here does not refer to a computer networks. When the name “network analyzer” was coined many years ago, there ware no such things as computer networks. Back then, networks always referred to electrical networks. Today, when we refer to the things that network analyzers measure, we speak mostly about devices and components. NanoVNA-F V3 is a dual-port portable vector network analyzer that can be used to measure the S11 parameters of a single-port network, or to measure the S11 and S21 parameters of a dual-port network. If you need to measure the S22 and S12 parameters of the dual-port network, you can achieve it by exchanging the measurement ports.
VNA must be calibrated before any measurements are performed. See section 4.4 for details。

Appearance

User interface

3.1. Main screen

1. START frequency
   The START frequency is shown in this area.

2. STOP frequency
   The STOP frequency is shown in this area.

3. Marker
   Up to 4 markers can be displayed at the same time.
   The active marker can be moved to any of the measured points in the following 2 ways:
   Push the UP or DOWN buttons.
   Drag the marker on the touch panel (recommend to operate with a stylus).

4. Calibration status
   O: Indicates OPEN calibration has been performed.
   S: Indicates SHORT calibration has been performed.
   L: Indicates LOAD calibration has been performed.
   T: Indicates THROUGH calibration has been performed.
   C: Indicates that the device has been performed a calibration.
   *: Indicates that the calibration data has not been stored and will be lost when power off.
   c: Indicates that the calibration data is Interpolated.
   Cn: Indicates that the corresponding calibration data is loaded (7 sets from 0 to 6).

5. Reference position
   Indicates the reference position of the corresponding trace. You can change the position by: 【DISPLAY】→【REF POS】

6. Marker Table
   Up to 4 sets of marker information can be displayed at the same time, each set of marker information includes frequency and 2 other parameters.
   The diamond mark in front of the marker table indicates which is the active marker.
   You can open, select or close a marker by: 【MARKER】→【SELECT】→【MARKER n】
   To quickly activate a marker, you can tap on the frequency value region of the corresponding
   row of the marker table (recommend to operate with a stylus).
   It is possible to move the marker table up and down by: 【MARKER】→【SELECT】→【POSITION】
   The marker table can be dragged when tap down and holding the measured value region of the
   marker table for more than 0.5 seconds;
   If you want to save the setting of marker table display position, you can do it by: 【RECALL/SAVE】→【SAVE】→【SAVE n】

7. Trace status box
   The status of each trace format and the value corresponding to the active marker are displayed.
   For example, if the display is showing：S21 LOGMAG 10dB/ 0.03dB, read it as follows:
   The cyan trace is current active
   Channel: PORT2 (transmission)
   Format: LOGMAG
   Scale is 10dB/div
   S21 value at current frequency is 0.03dB
   Tap on any set of trace status box will activate the corresponding trace.
   If the trace is active, tap on the specific region of the trace status box will trigger shortcuts:
   Tap on “channel” region (e.g., S21) will quickly switch channel;
   Tap on “format” region (e.g., LOGMAG) will quickly open the FORMAT menu;
   Tap on “scale” region (e.g., 10dB/) will quickly open SCALE and REFERENCE POSITION menu.

8. Battery voltage
   The voltage of the built-in lithium battery is shown here. If the battery voltage is lower than 3.3V,
   please charge the device.

9. Left ordinate
   The left ordinate always shows the scale label of trace 0.
   Tap on the area of left ordinate to quickly set the scale of trace 0.

10. Right ordinate
    The right ordinate always shows the scale label of current active trace.
    Tap on the area of right ordinate to quickly set the scale of current active trace.

11. Sweep points
    Show sweep points.

3.2. Menu screen The menu can be opened by the following operations:

• Tap on the specific area of the screen (shown in the red frame above).
• Press the middle button.

3.3. Keyboard screen The virtual keyboard includes numeric keys, backspace key, unit key, ok key.
Backspace key is used to delete one character. When the input box is empty, tap on the backspace key will close the keyboard.
Unit key(G, M, k) multiplies the current input by the corresponding unit and terminates input immediately.
Ok key equals to x1, in case of ok, the entered value is set as it is.
E.g.，：100kHz ：input 100 + k, or input 100000 + Ok；
433.92MHz ：input 433.92 + M；
2.4GHz ：input 2.4 + G；

Menus

4.1. DISPLAY
【DSIPLAY】menu contains【TRACE】,【FORMAT】,【SCALE】,【REF POS】,【CHANNEL】,【SWEEP POINTS】       4.1.1 TRACE
【TRACE】menu contains【TRACE 0】,【TRACE 1】,【TRACE 2】,【TRACE 3】. Tap on 【TRACE n】(e.g., 【TRACE 2】) will open and activate TRACE 2, and an □A marker will appear ahead of “TRACE 2”. Tap on another menu item (e.g.,【TRACE 3】) will open and activate TRACE 3, at this time, an □A marker will appear ahead of “TRACE 3”, and the □A marker ahead of “TRACE 2” becomes A , which means TRACE 2 and TRACE 3 are both opened and TRACE 3 is current active.
When a trace is active, the channel region of the trace in trace status box will be highlighted, as
shown in the figure above, S11 is highlighted.
Tap on the menu item with □A marker will close the corresponding trace.
4.1.2 FORMAT
【FORMAT】is used to set the format of traces. There are formats of LOGMAG, PHASE, DELAY, SMITH R+jX, SMITH R+L/C, SWR, Q FACTOR, POLAR, LINEAR, REAL, IMAG, RESISTANCE, REACTANCE.
LOGMAG ： the ordinate corresponds to logarithmic amplitude and the abscissa corresponds to frequency.
PHASE：the ordinate corresponds to phase and the abscissa corresponds to the frequency.
DELAY ： the ordinate corresponds to group delay and the abscissa corresponds to frequency. Only meaningful for S21.
SMITH R+jX：show impedance with Smith chart. Impedance is displayed in the form of R+jX. Only meaningful for S11.
SMITH R+L/C: show impedance with Smith chart. Impedance is displayed in the form of R+L/C, where R is the resistance value and L/C is the equivalent inductance or capacitance value.
Only meaningful for S11.
SWR：the ordinate corresponds to VSWR and the abscissa corresponds to frequency. Only meaningful for S11.
Q FACTOR ： the ordinate corresponds to Q factor, and the abscissa corresponds to frequency.
POLAR：show impedance in polar coordinates. Only meaningful for S11.
LINEAR：the ordinate corresponds to linear amplitude, and the abscissa corresponds to frequency.
REAL ： the ordinate corresponds to the real part of S parameter, and the abscissa corresponds to frequency.
IMAG：the ordinate corresponds to the imaginary part of S parameter, and the abscissa corresponds to frequency.
RESISTANCE ： the ordinate corresponds to resistance, and the abscissa corresponds to frequency.
REACTANCE ： the ordinate corresponds to reactance, and the abscissa corresponds to frequency.
There are 3 ways to activate a trace:
（1）【DISPLAY】→【TRACE】→【TRACE n】.
（2）Tap on the format region of the corresponding trace in the trace status box.
（3）Tap on any markers with the same color to the trace. 4.1.3 SCALE
【SCALE】is used to set the scale of the ordinate (not applicable to SMITH and POLAR formats).
4.1.4 REF POS
【REF POS】is used to set the reference position of the trace (not applicable to SMITH and POLAR formats). Ref pos is set to 7 by default, which corresponds to the 7th horizontal axis counting from bottom to top (0 corresponds to the bottom horizontal axis). Ref pos can be set to any integer.
4.1.5 CHANNEL
Tap on【CHANNEL】to switch the channel of current active trace.
4.1.6 SWEEP POINTS
Sweep points can be set from 11 to 801.
4.2. MARKER
【MARKER】menu contains【SELECT】,【SEARCH】,【OPERATIONS】,【SET FREQ】，【DRAG ON】. 4.2.1 SELECT
【SELECT】menu contains【MARKER 1】,【MARKER 2】,【MARKER 3】,【MARKER 4】,【ALL OFF】,【POSITION】. Tap on【MARKER n】(e.g.,【MARKER 2】) will open and activate MARKER 2, and an A marker will appear ahead of “MARKER 2”. Tap on another menu item (e.g., 【MARKER 3】) will open and activate MARKER 3, at this time, an A marker will appear ahead of “MARKER 3”, and the A marker ahead of “MARKER 2” becomes , which means MARKER 2 and MARKER 3 are both opened and MARKER 3 is current active.
Tap on the menu item with □A will close the corresponding marker.
The marker can be moved with the buttons only when it is active.
There are two ways to quickly activate a marker:
（ 1 ） Tap on the marker directly, as shown by the red arrow of the figure above (recommend to operate with a stylus).
（2）Tap on the frequency value region of the corresponding marker in the marker table, as shown in the red box of the above (recommend to operate with a stylus).
【ALL OFF】is used to turn off all markers at once.
【POSITION】is used to adjust the position of the marker table on screen. The marker table can be moved up and down to avoid occluding traces and markers.
It is possible to move the marker table by dragging: make sure that【DRAG ON】is enabled, and then tap on the marker value region (as shown in the green box of the figure above) and hold for more than 1 second, then you can drag and move the marker table freely (recommend to operate with a stylus).
4.2.2 SEARCH
【SEARCH】menu contains 【MAXIMUM】,【MINIMUM】,【SEARCH < LEFT】,【SEARCH > RIGHT】,【TRACKING】，and all the functions are effective for the currently active marker. 【TRACKING】is used to automatically track the maximum or minimum value of the trace. As shown in the figure above, if you want MARKER 2 to automatically track the minimum value of the S11 LOGMAG trace, firstly you should activate MARKER 2, and then tap on【MINIMUM】, and finally turn on【TRACKING】. After doing that, MARKER 2 will automatically move to the valley point of the S11 LOGMAG trace after each sweep.
4.2.3 OPERATIONS
【OPERATIONS】menu contains【>START】,【>STOP】,【>CENTER】,【>SPAN】.
【>START】：Set the frequency of the current active marker as the start frequency.
【>STOP】：Set the frequency of the current active marker as the stop frequency.
【>CENTER】：Set the frequency of the current active marker as the center frequency.
【>SPAN】：Set the frequency range between the current active marker and the next marker as the span. If there are no other markers behand the current active marker, the span will be set to zero.
4.2.4 SET FREQ
Tap on the menu to set the frequency of selected marker.It can also quickly pop up the menu by long pressing with the middle button.
4.2.5 DRAG ON
Enable/disable the drag-gable characteristic of marker table.
4.3. STIMULUS
【STIMULUS】menu contains【START】,【STOP】,【CENTER】,【SPAN】,【CW PULSE】, 【SIGNAL GENERATOR】,【PAUSE SWEEP】. 4.3.1 START
Tap on【START】to set the start frequency.
You can also tap on the red box area of the above figure to quickly set the start frequency.
4.3.2 STOP
Tap on【STOP】to set the stop frequency.
You can also tap on the yellow box area of the above figure to quickly set the stop frequency.
4.3.3 CENTER
Tap on【CENTER】to set the center frequency.
You can also tap on the red box area of the above figure to quickly set the center frequency.
4.3.4 SPAN
Tap on【SPAN】to set the frequency span.
You can also tap on the yellow box area of the above figure to quickly set the frequency span.
4.3.5 CW PULSE
Tap on【CW PULSE】to set the CW pulse frequency.
You can also tap on the red box area of the above figure to quickly set the CW pulse frequency.
Please note that in this mode the output of PORT 1 is pulse signal, not continuous wave.
4.3.6 SIGNAL GENERATOR 【SIGNAL GENERATOR】NanoVNA-F V3 supports simple signal generator function, which can be set as a single-frequency continuous wave generator with a frequency range from 1MHz to 6000MHz. RF power is adjustable above 23.5MHz.
【RF OUT】：Turn on/off the RF output.
【FREQ】：Set the frequency.
【0dB】：Output power attenuated 0dB.
【-3dB】：Output power attenuated 3dB.
【-6dB】：Output power attenuated 6dB.
【-9dB】：Output power attenuated 9dB.
4.3.7 PAUSE SWEEP
Tap on【PAUSE SWEEP】to pause sweep, tap again to resume sweep.
4.4. CAL
【CAL】menu contains【CALIBRATE】,【RESET】,【APPLY】.
4.4.1 APPLY
【APPLY】is turned on by default, indicating that the calibration data has been applied. Tap on 【APPLY】to turn it off. After doing that, the calibration status Cn at the bottom of the main screen will disappear, indicating that the measurement result is uncorrected. 4.4.2 RESET
Tap on【RESET】to clear the calibration data in the memory. After doing that, the calibration status OSLT Cn at the bottom of the main screen will disappear, but the calibration data stored in the internal FLASH will not be cleared. You can call back the calibration data to the memory by 【RECALL/SAVE】→【RECALL】→【RECALL n】 4.4.3 CALIBRATE
Tap on【CALIBRATE】to perform calibration. The following accessories need to be prepared before calibration:

1. SMA OPEN kit;
2. SMA SHORT kit;
3. SMA LOAD kit;
4. SMA-JJ RG405 cable;
5. SMA straight through adapter (optional);

Firstly, you need to set an appropriate frequency range, see section 4.3 for detail.
Tap on【CALIBRATE】to enter the calibration interface, and perform the calibration according to the following steps:
STEP ①
Connect the OPEN kit to PORT1 or the end of the cable connected to PORT1, as shown in the figure below:Tap on【OPEN】, the device emits a beep, and the menu turns gray and is inoperable. Wait for 2-3 seconds, the device emits a beep again, an □A marker will appear ahead of “OPEN”, and a letter “O” appears at the bottom of the screen, indicating that open calibration is finished.   NOTE: usually we need to connect the DUT to VNA with cables, at this time, the cable becomes a part of the measurement system, and the end of the cable should be treated as the VNA port during calibration.
STEP ②
Connect the SHORT kit to PORT1 or the end of the cable connected to PORT1, tap on【SHORT】to complete the short calibration.
STEP ③
Connect the LOAD kit to PORT1 or the end of the cable connected to PORT1, tap on【LOAD】to complete the load calibration.
STEP ④
Connect PORT1 and PORT2 with cable and adaptor (optional), as shown in the figure below, then tap on【THROUGH】to complete the through calibration. STEP ⑤
Tap on【DONE】, OSLT C* will appear at bottom of the screen, indicating that the calibration data has been generated but not yet saved. The save menu will appear on the right side of the screen at the same time. Tap on【SAVE n】to save the calibration data, and the frequency range of the calibration data will be display on the menu item. When properly calibrated, the VNA device should have the following characteristics:

1. When PORT1 is open-circuited, the S11 Smith trace converges on the far-right side of the Smith circle, the S11 LOGMAG trace is near 0dB, for S21 LOGMAG trace, the lower the better.
2. When PORT1 is short-circuited, the S11 Smith trace converges on the far-left side of the Smith circle, the S11 LOGMAG trace is near 0dB, for S21 LOGMAG trace, the lower the better.
3. When PORT1 is connected to a 50-ohm load, the S11 Smith traces converge at the center of the Smith circle. The lower the S11 and S21 LOGMAG trace, the better.
4. When PORT1 and PORT2 connected by a cable, the S11 Smith trace is near the center of the Smith circle, and the S21 LOGMAG trace is near 0dB. For S11 LOGMAG trace, the lower the better.

4.5. RECALL/SAVE
【RECALL/SAVE】menu contains【RECALL】and【SAVE】.
4.5.1 RECALL
Tap on【RECALL n】to recall calibration data and settings stored in slot n. The marker indicates which calibration data has been recalled.
4.5.2 SAVE
Tap on【SAVE n】to save calibration data and settings to one of 7 save slots.
4.6. TDR
NanoVNA-F V3 can be used as a time domain reflectometry, which is only meaningful for S11.
【TDR】menu contains【TDR ON】,【LOW PASS IMPULSE】,【LOW PASS STEP】,【BANDPASS】, 【WINDOW】,【VELOCITY FACTOR】.
Tap on【TDR ON】to enable TDR. Tap again to disable.
The relationship between time domain and frequency domain is as follows.

• Increasing the maximum frequency increases the time resolution.
• The shorter the measurement frequency interval (e.g. the lower the maximum frequency), the longer the maximum time length.

For this reason, the maximum time length and time resolution are in a trade- off relationship. In other words, the time length is the distance.

• If you want to increase the maximum measurement distance, you need to reduce the frequency spacing (frequency span / sweep points).
• If you want to measure the distance accurately, you need to increase the frequency span.

Connect a cable to PORT1, keep the other end of the cable open or short, move the marker to the peak of S11 trace, and the estimated cable length will be displayed on the screen.There are 3 kinds of digital processing mode available:【LOW PASS IMPULSE】，【LOW PASS STEP】,【BANDPASS】, and default setting is【BANDPASS】.
The range that can be measured is a finite number, and there is a minimum frequency and a maximum frequency. A window can be used to smooth out this discontinuous measurement data and reduce ringing.
There are three levels of windowing:【MINIMUM】，【NORMAL】,【MAXIMUM】, and default setting is【NORMAL】.
Velocity factor is defined as the ratio of the transmission speed of electromagnetic waves in the transmission line to the transmission speed of electromagnetic waves in vacuum.
Tap【VELOCITY FACTOR】to set the velocity factor. E.g. the typical velocity factor of RG405 cable is 0.7, you should input 70 via the virtual keyboard and end up with Ok, then the velocity factor will be set to 70%. NOTE: Use a lower frequency to measure a longer length and a higher frequency to measure a shorter length and adjust accordingly for accurate results.
4.7. CONFIG
【CONFIG】 menu contains 【ELECTRICAL DELAY】,【L/C MATCH】,【SWEEP POINTS】, 【TOUCH TEST】,【LANGSET】,【ABOUT】,【BRIGHTNESS】.
4.7.1 ELECTRICAL DELAY
【ELECTRICAL DELAY 】 is used to set a delay time in nanoseconds (ns) or picoseconds (ps) to compensate for the delay introduced by connectors or cables. 4.7.2 L/C MATCH
NanoVNA-F V3 supports automatic calculation of L/C matching parameters, matching the load impedance to the source 50ohm impedance.
The structure of L/C matching network is shown in the figure below: Example:
The measured load impedance is 25.9 28.9j, and VNA automatically generates four groups of available matching parameters:

1. 61.4pF capacitor for source shunt and 813pF inductor in series;
2. 164.4nH inductor for source shunt and 59.1pF inductor in series;
3. 83.2pF inductor for load shunt and 64.2nH inductor in series;
4. 39.0pF inductor for load shunt and 157pF capacitor in series.

4.7.3 DATA/TIME It used to set the real-time clock value. It can be set with the year, month, day, hour, and minute.
4.7.4 TOUCH TEST
【TOUCH TEST】is used to test whether the touch screen is normal. Press any button to exit the test.
4.7.5 LANGSET
Set language: Chinese or English.
4.7.6 ABOUT
You can check the hardware version, firmware version, serial number and supporting nformation,real time clock etc.
Each NanoVNA-F V3 device has a unique serial number, SYSJOINT provides after- sales service to customers based on this serial number.  4.7.7 BRIGHTNESS
The backlight brightness is adjustable in five levels: 100%、80%、60%、40%、20%.
4.8. STORAGE
【STORAGE】menu contains【S1P】,【S2P】,【LIST】.
4.8.1 S1P
S11 test results can be stored to the internal memory of NanoVNA-F V3 in the form of S1P files, which can be exported to PC with USB cable.
4.8.2 S2P
S11 and S21 test results can be stored to the internal memory of NanoVNA-F V3 in the form of S2P files, which can be exported to PC with USB cable.
4.8.3 LIST
List all the SNP files stored in the device.

User Defined Information

NanoVNA-F V3 supports displaying user-defined information on the boot screen. The setting method is as follows:

1. Create a text file named ‘callsign.txt’ on PC;
2. Open ‘callsign.txt’ and input the string which you want to be displayed on the boot screen (printable ASCII characters only, e.g., support@sysjoint.com). The maximum string length is 50.
3. Make NanoVNA-F V3 enter virtual u-disk mode, and copy ‘callsign.txt’ into the virtual u-disk.
4. Restart NanoVNA-F V3.

Dark mode

NanoVNA-F V3 supports dark mode:

1. Create a text file named dark_mode.txt on the PC.
2. Open dark_mode.txt and enter ”1”.
3. Connect NanoVNA-F V3 to PC with the USB Type-C cable, push and hold the middle push button, then power on NanoVNA-F V3. The device will be recognized as a U disk drive then copy the dark_mode.txt file to NanoVNA-F V3 U disk.
4. Restart NanoVNA-F V3.

PC Software

PC software download: http://www.sysjoint.com/file/Nanovna-Saver-0.3.12-by- SYSJOINT.exe
For Win10 system, you do not need to install the driver.
For Win8 and earlier versions of the Windows system, you need to install the driver: https://www.st.com/en/development-tools/stsw-stm32102.html
PC software provided by SYSJOINT only supports Windows system, Linux or MacOS version of the PC software is available from: https://github.com/NanoVNA- Saver/nanovna-saver/releases
Connect NanoVNA-F V3 to your PC with the USB Type-C cable, as shown in the figure below: Double click “nanovna-saver.exe” to run the PC software, and select the correct COM port. If there is no COM port detected, please click 【Rescan】.
After selecting the correct COM port, click【connect to device】to connect the device to PC. Through the PC software, you can set the start and stop frequency, get the measurement results, set the marker, take a screenshot, etc.
It is possible to get the device screen dump through the PC software:

1. Click【Manage】to open ‘Device setting’ dialog box.
2. Click【Screenshot】and wait for about 5 seconds.
3. Move the mouse to the image area, right-click and select “Save Image” to save the screenshot image to local disk.

Console Command

NanoVNA-F V3 supports character console commands, you can interact with the device through serial tools (such as PuTTY).
It is also possible to design a customized PC software according to the commands.
The serial port baud rate of NanoVNA-F V3 is adaptive, usually we choose a baud rate of 115200, as shown in the figure below: 8.1. Command Syntax
A command line is a string of characters sent from PC to NanoVNA-F V3. A command line has a command, a body, and a terminator. Each command line must begin with a command and must be terminated by a carriage return. The command line is a string of printable ASCII characters (032 – 126). Space characters (ASCII 032) and control characters other than CR (ASCII 013) and BS (ASCII 010) in the command string are ignored. The default terminator is the ASCII