RFbeam Microwave ST200 User manual

ST200 Radar Evaluation System
User Manual
© RFbeam Microwave GmbH www.rfbeam.ch January 2013 age 1/27

ST200 Evaluation System User Manual
Features
•Supports Doppler, FMCW, FSK, Monopulse
•USB Interface to Host Computer
•Onboard Low Noise ower Supplies
•Connectors for Different Radar Devices
•Amplifiers for Native Doppler Transceivers
•High erformance 16Bit Data rocessing
•250kSamples/s ADC and DAC
•Compact and Rugged Construction
•owerful Signal Explorer C Software
•NI LabVIEW ® DAQmx USB Interface
Applications
-Evaluation of Advanced Shortrange Radar Applications
-Development of Own Data rocessing Algorithms
-Signal Analysis and Logging
-Learning and Exploring Radar Basics
Description
ST200 is a 16Bit data acquisition and processing system with a total 250k/s sampling rate. It contains
all hardware necessary for acquiring Radar signals of RFbeam Transceivers.
ST200 contains a motherboard with power supply, amplifiers and I/O connectors. Data acquisition is
performed by a NI-USB-6211 16Bit multifunction DAQ module from National Instruments mounted on
the backside.
The easy to handle RFbeam Signal Explorer software features many basic Radar functions including
an exciting FSK (Frequency Shift Keying) operation mode for high resolution distance measurements
of moving objects.
ST200 Block Diagram
Radar Connectors:
X1: General purpose I/O
X2: Mixed I/O
X3: 4 Channel An. Inputs
X4: 2 Channel An. Inputs
X5: 2 Channel An. Inputs
Computer Interface:
X9: USB C ort
ower:
X10: Optional DC In
X11: Low Noise DC Out
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 2/27

ST200 Evaluation System User Manual
Getting Started
Please install so tware prior to connect ST200 to the USB port.
Equipment Needed
•ST200 Hardware
•ST200 Signal Explorer Software Installer on CD, USB stick or downloaded on HD
•USB cable
•K-LC2 sensor connected to connector X5
•C running on Windows xp or never
Installing Signal Explorer So tware
ST200 software comes with a setup procedure containing all necessary components into one single
package:
•RFbeam ST200 Signal Explorer Software
•National Instruments DAQmx ® driver software
•National Instruments LabVIEW ® runtime systerm
1. Start RFbeam Signal Explorer setup.exe from your intallation media
If your computer does not already contain a LabVIEW runtime engine and DAQmx driver, you
will be prompted to accept licences of National Instruments.
2. If possible, accept all default program locations. Troubleshooting will be simplified like this.
3. lease be patient while LabVIEW runtime system and DAQmx driver are being installed.
This may take some minutes...
4. Restart your computer, if asked so.
5. You will find SignalViewer under START-> ROGRAMS->RFbeam->Signal Explorer and a
shortcut icon on the Desktop.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 3/27

ST200 Evaluation System User Manual
Test Con iguration and Go!
We will now take a first impression by using the Doppler mode and observe movement of persons.
lease refer to the screen shot in Fig. 1
1. lug in a K-LC2 radar sensor into connector X5 of the ST200.
2. Connect ST200 hardware to you computer. There should appear a “New USB Hardware
Found” message from Windows.
3. Windows will probably ask you for a hardware driver. Select to find it aoutomatically.
4. Start SignalExporer under START-> ROGRAMS->RFbeam->SignalExplorer
After some seconds the main screen of the Signal Explorer should appear.
5. Select the most important controls according to Fig. 1 below.
6. Drag all 3 cursors as shown in Fig. 1 . If cursors are not visible, press cursor "Reset" button.
7. Now move your hands in front of the K-LC2 sensor. You will see the frequency and speed in
the upper graph and the time signal (oscilloscope) in the bottom graph.
8. Explore and become familiar with the effect of the 3 cursors.
9. Try to switch to Doppler- hase screen by using the left tab in the bottom half of the screen.
You will see the direction of your movement (Cursors must be set according to Fig. 1 ).
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 4/27
Fig. 1: Start Screen. Try to set all marked controls according to this igure
Y-range
Sensor configuration
Logarithmic display
Channel for FFT
Reset cursors to
visible area
Y-range
Channels to show
Detection area
defined by 3 cursors
Filter settings for time
domain
Time domain modes

ST200 Evaluation System User Manual
ST200 Hardware
ST200 consists of a mother board and a 16 Bit USB data acquisition system with 250kHz sampling
rate. The mother board contains 5V and 3.3V low noise power supplies and analog buffers and
amplifiers.
Sensor Connectors:
X1: General purpose I/O
X2: Mixed I/O
X3: 4 Channel An. Inputs
X4: 2 Channel An. Inputs
X5: 2 Channel An. Inputs
Computer Inter ace:
X9: USB C ort
Power:
X10: Optional DC In
X11: Low Noise DC Out
Fig. 3: Block Diagram
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 5/27
Fig. 2: Connector Arrangement
X1 X2 X3 X4 X5
X9
X10
X11
J 1 -> X1
3.3V / 5V
J 2 -> X2
Dig. I/O
J 3 -> X2,3
3.3V / 5V
J 4 -> X4,5
3.3V / 5V
ower Supplies
FM Level Shifters re-Amps

ST200 Evaluation System User Manual
Typical Sensor Connections
lease refer to Fig. 3 and to chapter Sensor Connectors for more details on tzhe connectors.
Sensors with higher current consumption (>120mA like K-MC4) need more power than USB can
deliver.
An external DC 12V power supply with >0.5A should be plugged into X10 of the ST200 system.
K-LCx Series → X5 or X4
Sensors of the K-LCx series with no internal amplifiers can directly be plugged into X5.
For remote connecting K-LCx sensors, a 6 pin ribbon flat cable my be connected to X4.
X5 or X4 provide 2 channels with amplifiers.
K-MCx and K-HC1 Series → X3
K-MCx sensors provide internal amplifiers and are typically connected to X3.
X3 provides 2 channels and is directrly routed to the DAQ system.
Notes:
- K-HC1 needs an own, separate power supply and a special adapter cable.
- K-MC4 can only be operated with an external 12VDC power supply connnected to X10.
Other Sensors
lease contact RFbeam for instructions on connecting special sensors.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 6/27

ST200 Evaluation System User Manual
Signal Explorer So tware
Overview
Getting Help
Most controls and readouts provide a context help on mouse over.
Select Help - Show ContextHelp from main menu. This opens a floating window containing a brief
description of the object pointed by the mouse cursor.
Operation Modes
ST200 Signal Explorer provides 3 main operation modes:
•Doppler Mode: Speed and direction measurements
•FMCW Mode: Distance measurements of statical and moving objects
•FSK Mode: Distance measurements with high resolution for moving objets
User interface includes selecting of operation modes and sensor types, setting of filter types and
bandwidth, sampling rates, graphical representation of signals in time and frequency.
User inteface screen is devided into 3 sections:
Fig. 4: Screen Sections
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 7/27
General Section
Operation Section
Recorder Section

ST200 Evaluation System User Manual
General Section
Settings and readouts in the general screen section (see Fig. 4) are accessible in all operation modes.
Readouts
Samples: Number of samples per channel as input for the signal processing (FFT).
Rate: ADC sampling rate per channel.
Loop Time: Time to read the samples defined in the selected configuration. It is calculated by
Con igurations Selector
Many key settings are stored as so called configurations. Existing configurations may be selected at
any time. After selecting, Signal Explorer jumps back into operation mode Doppler.
Configuration naming convention:
K-LC2_X4-5_IQH.cfg
| | |_ connector inputs
| |____ connector name(s (refer to chapter Sensor Connectors
|__________ sensor type
Con igurations Setup
You may alter or copy existing configurations. New configurations may be generated.
Refer to chapter Settings for more details.
Operation Section
This is the real time signal section (see Fig. 4).
Select the operation mode with the horizontal tabs on the top. Some modes allow selecting sub-modes
by the vertical tabs in the bottom left part of the operation section.
Recorder Section
ST200 Signal Explorer allows real time recording and playback of signals captured in the Doppler and
in the FSK mode.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 8/27
looptime=number of samples
samplingRate

ST200 Evaluation System User Manual
Using Signal Explorer So tware
Doppler Mode
About Doppler Radar
A more precise tiltle would be 'CW (Continuous Wave) Doppler Radar', when using RFbeam Radar
sensors. These sensors do not produce pulses, but send continuously in the K-band (24.125 GHz ).
The sensors are also called Radar transceivers, because they include a Transmitter and a Receiver.
Doppler Radar is used to detect moving objects and evaluate their velocity. More details on the
principle can be read here:
http://en.wikipedia.org/wiki/Doppler_radar
http://www.radartutorial.eu/11.coherent/co06.en.html
RFbeam Radar transceivers return a so called IF signal,
that is a mixing product of the transmitted (Tx) and the
received (Rx) frequency. An moving object generates a
slightly higher or lower frequency at the receiver. The IF
signal is the absolute value of the difference between
transmitted and received frequency.
These transceivers operate in the CW (Continuous Wave)
mode as opposed to the pulse radars, that measure time
of flight. CW radars can operate with very low transmit
power (< 20dBm resp. 100mW).
Calculating the Doppler requency
fd=2⋅fTx
⋅v
c0
⋅cos α
(1)
or
v=c0
⋅fd
2⋅fTx ⋅cos α
(2)
fd Doppler frequency
fTx Transmit frequency (24GHz)
c0 Speed of light (3 * 108 m/s)
vObject speed in m/s
αAngle between beam and object moving direction
At a transmit frequency of fTx = 24.125GHz we get a Doppler frequency for a moving object at the IF
output of
fd=v[km/h]⋅44Hz⋅cos α
or
fd=v[m/s]⋅161Hz⋅cos α
(4)
Angle α reduces the measured speed by a factor of cos α.
This angle varies with the distance of the object.
To evaluate the correct speed, you need a trigger criteria at a
known point. This can be accomplished by measuring the
distance with the radar sensor (e.g. using FSK technology) or
by measuring the angle using a monopulse radar such as
K-MC4.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 9/27
Fig. 6: De inition o angle α
αmoving
object
Radar sensor
Fig. 5: Typical Radar Transceiver
K-LC1a
Tx Rx
IF output
FM Input

ST200 Evaluation System User Manual
ST200 Doppler Mode
Note the difference between logarithmic (upper figure) and linear (bottom figure) FFT display. Smaller
peaks in logarithmic display disappear in linear display.
Note the difference: in linear mode, small signals and noise disappear.
Remember to reset cursors after switching between logarithmic and linear mode.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 10/27
Fig. 8: Linear FFT scale
Linear display
Fig. 7: Logarithmic FFT scale
Logarithmic/Linear
display
Cursor low freq. limit Cursor high freq. limit
Low amplitude limit
Reset cursors to visible
area
Filter for time signal
bandwidth

ST200 Evaluation System User Manual
Chart Modes
Besides the classical scope modes, ST200 allows “chart” modes for viewing slow signals.
Zooming and shi ting charts
Data for the charts come from the signal buffer. Scaling is performed on display level and not on signal
level. This allows scrolling and zooming.
Charts may be zoomed by changing the Y range and/or by changing the horizontal chart speed.
Charts may be “freezed”. Freezed charts may be horizontally scrolled over a history of around 1 million
samples.
Signal chart mode
The “Signal chart mode” (Fig. 9) is similar to the scope mode, but writes the signal on a slow moving
chart. This is useful for visualization of very slow signals.
You may (and should) downsample the signal, so that not all the signal buffer will be written to the
chart. Set the decimation factor to the highest possible value, but smaller than the number of samples
(in this example 8192) defined in the configuration.
This process is called decimation or resampling. It includes anti aliasing adapted to the new sampling
rate:
fs(chart)=sampling rate per channel
decimation factor
→ Example in Fig. 9
The reduced sampling rate limits upper frequency in chart to 0.4 * fu = 12.5kHz in our example.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 11/27
Fig. 9: Signal chart mode. Slow chart, high requency → Envelope chart
Decimation factor Resulting sampling rate
125kHz
4=31.25kHz

ST200 Evaluation System User Manual
Signal chart mode - very slow signals
Note: "Suppress DC" checkbox should be uncheckt. Otherwise slow signal will be interpreted as DC
and removed or distorted.
RMS chart Mode
The “RMS chart mode” traces the RMS amplitude of the selected peak in a chart.
Fig. 11 shows an RMS amplitude chart of a selected peak. The amplitude drops to 0, as soon as the
peak in the FFT falls outside the selected area. In our example, it dropped under the minimum level
selected by the horizontal cursor.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 12/27
Fig. 10: Signal chart mode, very low requency (record o human breathing)
Fig. 11: RMS chart mode. Traces the selected peak's RMS amplitude

ST200 Evaluation System User Manual
Exploring the phase relation
hase relaion bewtween two channels can be evaluated by using "cross FFT" algorithms (Fig. 12) or
by using "complex FFT" (Fig. 13).
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 13/27
Fig. 13: Complex FFT with one approaching target: peak on right side
Fig. 12: Display I and Q phase relation to evaluate moving direction
Complex FFT
Time signal display
receding targets approaching targets
hase display
Target is receding
I and Q channel selected
Target is approaching

ST200 Evaluation System User Manual
FMCW Mode
About FMCW
FMCW stands for Frequency Modulated Continuous Wave. This technique allows detection of
stationary objects. FMCW needs Radar sensors with an FM input. This input accepts a voltage that
causes a frequency change. There are also sensors with digital frequency control based on digital LL
designs. Modulation depth is normally a very small amount of the carrier frequency. In the K-band,
most countries allow a maximum frequency range of 250MHz.
Descfription of many effects such as velocity-range unambiguities go beyond the scope of this paper.
lease refer to Radar literature for more detailed explanations of FMCW and FSK techniques.
Sawtooth Modulation
Transmit frequency is modulated by a linear ramp. Fig. 14 shows a typical signal fRx returned by
stationary and constantly moving objects. Note, that the difference frequency fb is constant throughout
nearly the whole ramp time.
At the output of the Radar transceiver we get the low frequency signal fb called beat frequency. This is
the result of mixing (=multiplying) transmitted and received frequencies (refer to Fig. 5).
Sawtooth modulation has important disadvantages:
•It is very difficult to get reliable results for moving objects
•The very sharp down ramp can disturb the amplified signals (ringing, saturation)
Returned echo rom stationary object
fMModulation depth
TMModulation period
fTx Transmitted frequency
fRx Received frequency
tpSignal propagation time (time of flight)
fb Beat frequency fTx - fRx
fD Doppler shift frequency
Fig. 14: Sawtooth modulation
Above: Stationary object, Below: Moving object
Returned echo rom moving object
Received frequency fRx is shifted by fD .
This is the Doppler frequency caused by a
receding object moving at a constant speed.
Distance can be calculated as follows:
R=c0
2⋅fb fM
⋅TM
(5) For legend refer to Fig. 14 above
R Range, distance to target
c0 peed of light (3 * 108 m/s)
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 14/27
fD
tp
f
t
fb
fTx
fRx
fM
TM
tp
f
t
fb
fTx
fRx
fM
TM

ST200 Evaluation System User Manual
Triangle Modulation
Transmit frequency is modulated by a linear up and down ramp. Fig. 15 shows a typical signal fRx
returned by stationary and constantly moving objects. Note, that the difference frequency fb is constant
throughout nearly the whole ramp time.
At the output of the Radar transceiver we get the a low frequency signal fb called beat frequency. This
is the result of mixing (=multiplying) transmitted and received frequencies (refer to Fig. 5).
Returned echo rom stationary object
fMModulation depth
TMModulation period
fTx Transmitted frequency
fRx Received frequency
tpSignal propagation time (time of flight)
fb Beat frequency fTx - fRx
fD Doppler shift frequency
Fig. 15: Triangle modulation
Above: Stationary object, Below: Moving object
Returned echo rom moving object
Received frequency fRx is shifted by fD .
This is the Doppler frequency caused by a
receding object moving at a constant speed.
By measuring during up and down ramp,
Doppler frequency fD is the diffence between
fb1 and fb2 .
Distance can be calculated as follows:
R=c0
2⋅fb fM
⋅TM
2
(7) For legend refer to Fig. 15 above
R Range, distance to target
c0 peed of light (3 * 108 m/s)
Maximum unambiguous range:
Rmax=c0
2⋅TM 2
(8) For legend refer to Fig. 15 above
Rmax Max. unambiguos target distance
c0 peed of light (3 * 108 m/s)
Advantages of triangle modulation:
•Doppler frequency can be determined
•IF amplifiers are less stressed than with sawtooth modulation
Advanced FMCW Modulation Techniques
Triangle modulation may be extended with phase of constant frequency to allow Doppler detection.
You find examples in chapter Exploring FMCW.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 15/27
f
t
fD
fTx
fRx
fMfb1
TM
fb2
f
t
fTx
fRx
fMfb
TM
tp

ST200 Evaluation System User Manual
Distance and Resolution
In K-Band (24GHz), maximum allowed frequency modulation depth fM is < 250MHz. We also have to
take in account tolerances and temperature influences. This limits the usable frequency shift fM to
typically 150MHz
For measuring fb to evaluate distance we need at least one period of fb during TM , range resolution is
limited to
Rmin=c0
2⋅fM
=38m/s
2⋅250MHz =0.6m
(6) This is a theoretical value, because we have to
take in account drifts and tolerances in order to
stay in the allowed frequency band.
Working with the more realistic value of fM = 150MHz, we get a minimum distance and resolution of
R = 1m .
Resolution may be enhanced by using phase conditions, correlation and other sophisticated
algorithms.
Real World E ectsSel -Mixing Crosstalk
FM modulation with radar transceivers can produce side effects. Most annoying effect is caused by the
feed through of the modulation signal to the IF output. This effect is caused by the limited isolation
between transmitter and receiver path and can be called self-mixing. This effect limits the minimal
detectable distance. This signal also limits the maximum signal amplification.
a) VCO modulation signal c) FFT of the signal sensor output signal b)
b) Resulting sensor output with target in 5m
Left picture b) shows the I and Q signals of a K-
MC1 sensor. Target has a distance of 5m. Self
mixing signal is much higher than the reflected
sinus signal of the target.
FFT in picture c) shows, that target signal is very
close to the self mixing signal.
Fig. 16: FMCW e ect o sel mixing
Similar effects may be caused by poor quality of the cover in front of the sensor antenna. The cover is
often called RADOM (from Radar Dome). The reason is different reflectivity at different frequencies.
lease contact RFbeam for more informations on Radom.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 16/27
Target

ST200 Evaluation System User Manual
Linearity
Non-linearity reduces resolution and sensitivity in FMCW ranging applications.
Linearity of the frequency ramps is crucial for reliable distance information. Varactor based open loop
oscillators suffer of non linearities, that must be corrected by the FMCW VCO voltage generator.
RFbeam Signal Explorer offers tools to calculate and compensate non linearities. We will explain this
later.
Exploring FMCW
FMCW may be best explored by using RFbeam K-MCx sensors. These sensors have enough
sensitivity and beam focussing to demonstrate FMCW for many applications.
Best experience can be obtained by placing the Radar sensor outdoor. Fig. 17 shows an
example of a signal from a sensor placed outside an office window.
lease note that some window types may absorb Radar signals, if they contain metallic
components.
Bottom right graph in Fig. 17 demonstrates a calculated VCO ramp (yellow) to get a linear frequency
ramp (blue). For more details on linearization refer to chapter FM Linearization.
Doppler FFT is displayed only, if VCO ramp contains a third, constant frequency block (called "3-
blocks" FM Type).
In FMCW mode, the number of samples is defined by the definition of the VCO ramp. Refer to
chapter FM Ramp Definitions.
Try using "Learn" button to mask out the momentary FMCW objects in FFT readout.
Select then "Diff" display. In this mode with linear FFT (Vrms) readout, be sure to extend
range of Y axis to negative values also.
This allows better viewing changed situations in the environment.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 17/27
Fig. 17: ST200 FMCW Screen Overview using a K-MC1 sensor.
VCO ramp
Freq ramp
Object in 39.5m
Distance at cursor position
VCO Linearization
ON/OFF
VCO Linearization
Tool
No Doppler phase:
Readout is disabled

ST200 Evaluation System User Manual
FSK Mode
FSK stands for Frequency Shift Keying. FSK uses two discrete carrier frequencies fa and fb, (Fig. 18)
while FMCW uses linear ramps.
For each carrier frequency, separate IF signals must be sampled in order to get 2 buffers for separate
FFT processing.
Due to the very small step fa - fb a moving target will apear at the nearly the same Doppler frequency
at both carriers, but with a different phase (Fig. 19) .
hase shift due to the modulation timing and sampling must also be taken into account.
faCarrier Frequency a
fbCarrier Frequency b
txa ampling point for Doppler a
txb ampling point for Doppler b
witching must be performed at a sampling rate
high enough to meeting the Nyquist criteria for the
Doppler signal acquisition.
IF(txa) ensor output signal at Carrier Frequency fa
IF(txb) ensor output signal at Carrier Frequency fb
Doppler signals of the same moving target have
same frequency, but are phase shifted by Δφ
For both IF signals, phase must be determined at
the spectral peak of the object.
R=c0
⋅Δ φ
4π⋅( fa−fb)
(7) Δφ Phase shift of IF(txa) and IF(txb)
φ ranges from 0 to 180°
ign of φ indicates moving direction
The smaller the frequency step, the higher the maximum range.
With a frequency step of 1 MHz, you will get unambigous distance range of 75m.
•FSK can only be used for moving objects
•Multiple objects at different speeds may be detected
•Distance resolution depends manly on signal processing and is not limited by the carrier
bandwidth limitations
•FSK has the advantage of simple modulation and does not suffer from linearity problems
•VCO signal generation is simple, but sampling and phase measurement is challenging
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 18/27
Fig. 18: FSK modulation scheme
t
f
fa
fb
Tb
Ta
txa txb txa txb txa txb
Fig. 19: Resulting Doppler requencies
IF(txa)
IF(txb)

ST200 Evaluation System User Manual
Exploring FSK
The power of FSK may be best explored by using the simple K-LC1a or other K-LCx series
sensors. You may check the functionality by walking around in front of these sensors.
lease note, that FSK allows even moving direction detection with the 1 channel K-LC1.
Technical Background
ST200 generates a continuous rectangular signal stream at the VCO input of the Radar sensor. With a
strict and jitter free clock, two signal buffers, one for fa, one for fb. (see Fig. 18), are generated from the
sensor IF output. Sampling rate of each buffer is normally ¼ of the sampling rate of the analog output.
This rate may be changed using the setup feature described in chapter Configurations Setup.
Both buffers are fed into the 2 inputs of a cross FFT, that allows measuring the phase for each
spectral line.
hase (=distance) is displayed on Signal Explorer for the highest level spectral peak only. But FSK
would allows detecting distances of many targets with different speeds.
FSK is possible even with RFbeam's low cost sensor K-LC1a.
Recording in FSK mode is possible. This allows analyzing situations under laboratory conditions.
lease select an appropriate area by means of the cursors in the FFT graph.
hase calculation can be performed for each single frequency. In ST200, only the highest
peak in the capturing area is taken in account.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 19/27
Fig. 20: FSK using K-LC1a: moving person, stopping or 1 second
Select capturing area
with cursors
Frequency step
Distance chart speed
standing still
→ hold time
Hold time if speed = 0

ST200 Evaluation System User Manual
Recording and Playback
ST100 allows recording and playing back Radar signals. Data is stored in multichannel TDMS files
according to the National Instruments ® standard. There is no compression. Sampling rate in the file
corresponds to the main sampling rate.
Following items are stored in the TDMS file:
Channel related:
- Channel (= Signal) Name
- Data length
- Samples/cycle
- Date/time of recording start
Administration:
- Sensor Name
- Author (user name of C)
- Notes (not used yet)
- Configuration Name
- System Mode (Doppler, FSK)
FMCW recording is not supported in the current Signal Explorer version
Recording produces very long filels, depending on sampling rate, number of channels and
recording duration.
Limiting ile size
You may limit stream file size with different method:
1. Limit size by file size
2. Limit size by recording time
3. Split recording into multiple, size limited files. Multiple files will be numbered automatically.
lease find more details on TDMS file format on http://zone.ni.com/devzone/cda/tut/p/id/3727.
© RFbeam Microwave GmbH www.rfbeam.ch January, 2013 age 20/27
Fig. 21: Unlimited stream Fig. 22: 4 iles limited to 10MB each
Fig. 23: Resulting iles in Multi File mode selected as in Fig. 22