F.A.Q. oscilloscope

1.1  What is an oscilloscope?
Unlike the voltmeter, with an oscilloscope you can not only see the mean values of the voltage in the circuits measured, but also the change and shape of that voltage through time. All oscilloscopes have screens on which the waveform is shown. The screen can be a cathode-ray tube type, a liquid crystal display (LCD) or in the form of a computer program. The typical oscilloscope screen is divided into equal spaces (divisions) which allow to visually interpreting the parameters of the signal. The graphics shown on the monitor are called waveforms. Usually oscilloscopes show only voltage waveforms. This form of visualization shows the change of voltage through time. The divisions marked on the horizontal(x) axis allow for the time parameters to be measured, and the vertical(y) axis allow for the voltage values to be measured.

1.2  What’s a universal oscilloscope?
Universal oscilloscope is an electronic measuring device used only for observing electrical voltage through time. The screen of the oscilloscope shows the changes in one or more input signal over time in an X-Y display, allowing for the amplitude and shape of the voltage to be accounted, as well as making phase and frequency measurements of the signal. In order for the oscilloscope to observe other physical parameters, as well as observing voltages outside its original ranges different types of additional attachments and transformers that convert the given input into voltage are used.

1.3  What purposes have oscilloscopes in auto diagnostics?
The oscilloscope helps us find the problem quicker and easier. Often the problem hasn’t recorded an error code (DTC) in the corresponding ECU. DTCs that can be read with a code reader. Usually a DTC is recorded when there is a broken cable or a cable has short circuited to a positive or negative supply. But when a sensor or a mechanism has stopped working in some mid position, there is no error recorded. In this case, as when you need to find the reason that caused an error to be recorded – the automobile oscilloscope is your most needed instrument. With the increase of sensors, actuators and wiring diagrams built in the modern automobiles, the automotive oscilloscope is an instrument which diagnoses irregularities in the automobile faster and easier. The oscilloscope is irreplaceable tool, when you have to observe output signals from inductive sensors, whose output signals form impulse sequence, slow-changing analog signals, primary and secondary ignition circuits, intake manifold absolute pressure, starter current waveforms, charging currents and etc.

1.4  What is the difference between a motor tester and a lab scope?
The motor tester is one kind of specialized oscilloscope used for auto diagnostics. The main difference between a motor tester and a universal oscilloscope is that the motor tester is capable of visualizing short-timed processes like the ignition spark process. This process is exceptionally fast, and the period of repeat of the ignition of sparks in time is many times greater than the time the spark itself exists. This is easily observable when testing the engine on idle speed, when the majority of the measurements are conducted. For example if we observe the ignition cycle of a 4 cylinder  gasoline engine, and the ignition spark lasts around 2ms, at 800 RPM, the time period between sparks on a single cylinder would be 150ms. What this means is that the ‘length’ of the spark would account for around 2% of the actual work cycle, and therefore the burning of the sparks will be seen as very thin lines on the screen of the oscilloscope, and no information about the phases of the ignition would be seen. Because of this many diagnostics are forced to increase the RPM of the engine thus shortening the ignition cycle thus ‘saturating’ the waveform of the cycle.
The motor tester shows all the cylinders simultaneously, and allows for detailed observation of the time period that includes: dwell period, drilling voltage, burn time and turbulence of voltage. Most motor testers can show the cylinders graphs next to each other, or under one another, excluding the long time periods between sparks, this method is also known as “parade”. Another distinctive feature of the motor tester is that it can show its time divisions on its horizontal (x) axis in milliseconds as well as in degrees – up to 720 degrees.

1.5  Features that allow PC-based oscilloscopes to be used in auto diagnostics.
It costs lower than a stand-alone oscilloscope, assuming the user already owns a PC. Easy exporting of data to standard PC software such as spreadsheets and word processors. Device software can be directly installed on a PC and upgraded via CD or directly download from the Internet without having to send the device back to its manufacturer. Use of the PC's disc storage functions, which cost a lot extra when added to a self-contained oscilloscope. PCs typically have large high-resolution color displays which can be easier to read than the smaller displays found on conventional scopes. Color can be utilized to differentiate waveforms.

1.6  What are the computer requirements for a CarScope program?
You need a computer (laptop, netbook, tablet or a desktop PC) running Microsoft Windows.
Operating Systems: Windows XP, Windows 7, Windows 8.1 or 10; 32-bit / 64-bit
We recommend at least a 1.5 GHz (Win XP) CPU, 1GB of RAM and Windows XP or newer.  With Windows 7, 8.1 or 10, use a machine robust enough to properly support the operating system.
CarScope program requires less than 200 MB hard disk space.
Screen resolution can be as low as 1024x768, but more is recommended.
If the oscilloscope is CarScope Pro (Wi-Fi), a Wireless Wi-Fi Network adapter compatible with IEEE 802.11 b/g standard must be installed.

1.7  Will CarScope program work on Windows 10?
Yes, the current version of CarScope is compatible with Windows 10. But .Net Framework 3.5 must be pre-installed in Windows 10. See “How to install .Net Framework 3.5 on Windows 10?”

1.8  Will CarScope program work on Microsoft Surface tablets?
There are two versions of these tablets, "Surface" and "Surface Pro". The regular "Surface" tablets are based on ARM CPUs running "Windows RT" and have no compatibility with normal Windows x86 programs.  The CarScope program will not work on these. The "Surface Pro" tablets use Intel CPUs and Windows 8, and CarScope will work fine on them.

1.9  If I need to have more than 4 channels, can I use 2 CarScope devices at the same time in one PC?
No, you can’t do this.

2.1  What is the accuracy of an oscilloscope?
The accuracy of an oscilloscope refers to how much its measured values deviate from the truth. To be meaningful, accuracy must really refer to "worst case accuracy".
Also see “What does <calibration data> mean?”

2.2  What does the “calibration data” mean?
All electronic components in the oscilloscope have some tolerance. In the worst-case accuracy measuring error could reach more than 5%. The “calibration data” are data that are specific to each unit and they are pre-saved inside the firmware.
When PC software receives data from the oscilloscope, it’s calculated in order to improve the measurement accuracy.

2.3  Is a long Memory really important?
The memory depth is quite sufficient for all automotive signal measurements.Thelength of the memory have a direct impact on thesample rate that is set and hence the effective bandwidth and reproduction quality. The Memory lengthdetermines thesampling rate.

2.4  What size is the CarScope devices memory depth?
See the specification section for each CarScope device.

2.5  What does a “sample rate” mean?
The sample rate of an oscilloscope is the clock frequency of its analog to digital converter or the number of times per second that the DSO (digital signal oscilloscope) samples the circuit under test. It limits the highest signal frequency, which could be properly analyzed by the oscilloscope. Depending on whether each measuring channel has its own ADC or all channels share a single ADC, the sampling speed may depend on how many channels are simultaneously used. Usually ADC clock frequency of 10MHZ per channel is quite sufficient.

2.6 What does a “bandwidth” mean?
The most familiar specification frequently used to gauge the performance of oscilloscopes is bandwidth. Bandwidth is a specification that defines the highest frequency electrical signal that the scope can display. The effective bandwidth of a DSO is mainly determined by the sample rate. More precisely the effective bandwidth is usually three times lower than the sample rate. Unnecessarily high bandwidth will result in noise or unwanted signals showing up on your labscope screen. The problem of waveform interpretation, already challenging, is made more difficult when the labscope bandwidth is not matched to the measurement task.

2.7 What is oscilloscope resolution?
The ability of an oscilloscope to resolve small voltages is called "oscilloscope resolution". Resolution depends on several oscilloscope parameters:
  • The number of bits of the embedded analog to digital converters. Usually vertical resolution of 8 bits is quite sufficient for all automotive applications;
  • The ADC’s reference voltage;
  • Input attenuator circuit;
  • Type of the input signal preamplifier if it is exists.

3.1 Is the CarScope Pro main program free to download?
Yes it is free to download. Just go to the download section of the website.

3.2 Is there a need to have pre-installed specific Windows drivers for CarScope?
No, it is not necessary to install a specific driver such like an USB device driver. Although it is necessary to check that there is a working LAN/Wi-Fi network card installed with the latest drivers.

3.3  Where can I check what is the current version of the program that is used?
Open the CarScope program and go to Help → About. See the text “Software Version XX.X” where XX.X is the version of the CarScope program.

3.4  How to install .Net Framework 3.5 on Windows 10?
Please type in an internet search engine like Google, Bing or other the same question.
For example1:
For example2:

3.5  How to keep already saved measurements if I upgraded CarScope program with new version?
You should go to the installation folder (usually C:CarScope) and back up the “Saved Measurements” folder somewhere.

3.6  How to keep already saved waveforms if I upgraded CarScope program with new version?
You should go to the installation folder (usually C:CarScope) and back up the “Saved Waveforms” folder somewhere.

3.7  How can I run the CarScope program at a higher priority in Windows?
Press Ctrl+Alt+Del simultaneously and a pop up window will appear → choose Start Task Manager  → Processes → CarScope Pro.exe → right mouse button → Set Priority → Choose the Realtime option. This is necessary in order to make waveforms on screen look smoother and more accurate.

3.8  Is there a detailed help system included how to work with the CarScope program?
Yes! There are two variants of the help system. The general help is accessed by pressing the "Help" button like as many other programs. The second help is context-sensitive that is obtained from a specific point in the state of the software, providing help for the situation that is associated with that state. Each topic of it describes how to connect the oscilloscope, what probes should be used, the required settings of the oscilloscope needed in this situation and etc.

3.9  Is it possible to use CarScope program with an oscilloscope made by another producer?
No, that is impossible.

3.10  Is it possible to use any of CarScope devices with a program developed from another producer?
Yes, it is possible but this program must be written for CarScope.

4.1  Where can I check what is the serial number of my hardware unit?
Power on the CarScope device. Connect to the CarScope Wi-Fi network in Windows (if you use the CarScope Pro device) or connect the LAN cable (for CarScope LAN and PLUS). Open the CarScope program and press the Connect button to establish connection with the CarScope device. After successful connection go to Help → About. See the text “Serial number: xxxxxxxxxxxx” where xxxxxxxxxxxx is the 12 digit serial number of your CarScope device.

4.2  Where can I check what is the current version of the embedded firmware?
Power on the CarScope device. Connect to the CarScope Wi-Fi network in Windows (if you use the CarScope Pro device) or connect the LAN cable (for CarScope LAN and PLUS). Open the CarScope program and press the Connect button to establish connection with the CarScope device. After successful connection go to Help → About. See the text “MCU FW: XXXX” where XXXX is the 4 digit number representing the MCU firmware version of your CarScope device.

* If you use the CarScope Pro device (Wi-Fi) you can also see the firmware version of the embedded Wi-Fi module. Look at the “Fi-Wly:” section.

4.3  What is the function of the LED on the back of the box of CarScope LAN and PLUS?
This LED determines the “Connection status” of the CarScope LAN or PLUS device.
When the device is powered on, the LED starts flashing. When a successful connection with the CarScope LAN or PLUS device has been established (through the CarScope program), the LED lights continuously (not flashing).

4.4  What is the function of the green and the red LEDs on the back of the box of CarScope Pro?
Red LED is for “WiFi reset” of the embedded Wi-Fi module. When the CarScope Pro device is powered on, red LED lights up and goes off in about 10 seconds.
Note: “WiFi reset” LED is available only on CarScope Pro device (with Wi-Fi connection)! CarScope LAN and CarScope PLUS devices have only one LED for “Connection status”! These devices don’t have the “WiFi reset” LED!

4.5  How to update the CarScope device firmware?
Go to the Downloads section for each CarScope device and follow the instructions.

4.6  Can I use the same CarScope device on several computers?
CarScope program can be installed on any Windows based computer. Each of them will work correctly with the CarScope main device. But this cannot be done simultaneously on two and more computers.

5.1  What is the difference between CarScope PLUS, CarScope LAN and CarScope Pro?
See the page “Comparison of CarScope automotive scopes”

5.2  Can I use CarScope to measure primary and secondary ignition patterns?Absolutely, 100%. Each model CarScope is a high efficiency ignition analyzer. They are specially designed for automobile test and analysis of ignition systems. Ignition waveform test function can be used to test the primary and secondary ignitions. Their waveforms are displayed as a single cylinder waveform as well and a parade waveform. It can be used to test all kinds of ignition systems: with or without distributor as well as Coil-on-Plug (COP) systems. 

5.3  Why I cannot synchronize the four cylinders on the screen in DIS ignition?
If a waveform cannot be seen stable on the display, this could be because the level of synchronization is not properly settled. If, however, waveform cannot be seen stable on the display, this could be because signal polarity is opposite. To see a stable waveform you must change the Channel B and the Channel C secondary pickup clips places.

5.4  What is the difference between wired (LAN) and wireless (Wi-Fi) kind oscilloscopes?
The main difference with CarScope Pro (Wi-Fi) and both other oscilloscopes is the significantly increased communication speed between the PC and the oscilloscope in the LAN variant (in the variant with wire).
The faster sample rate and the quicker response time make waveforms look smoother and more accurate on the screen.
At the same time we have kept all the advantages of the Ethernet network protocol:
  • Galvanic isolation between the computer and the oscilloscope;
  • Lost data packet recovery for reliable delivery;
  • Great common mode rejection: minimizes static discharge noise, magnetic fields and radio frequency interference.

5.5  Is there a waveform library included with the CarScope program?
CarScope software program includes an extensive automotive library to compare the signals and a help system to work with it. It can record all measurement results for later analysis or to create a typical faults database. Also there are several "presets" that will allow you to just hook up and go without the need to set a voltage scale, trigger or time base.

5.6  Does the CarScope device come with measuring probes?
See the Accessory section on the product page you have interested in. All others probes you can see on our website.

5.7  What's the difference between a CarScope automotive oscilloscope and a scan-tool?
Scan tools and automotive oscilloscopes do different jobs. Diagnostic trouble codes from your scan tool are always the first choice. But when this is not enough and the problem is difficult to detect, a further diagnosis and testing is required and this is where an automotive diagnostic oscilloscope becomes invaluable. So, an automotive repair shop needs both.

6.1  Why not USB?
Our experience with large amount USB oscilloscopes proves that there are many overpowering communication problems. In some of the automotive measurements USB communication is not reliable such as measurements of the secondary circuit ignition, piezo injector‘s signal and etc.

6.2  Why we use the TCP IP protocol for communication?
TCP IP protocol is very reliable. If for some reason there is a little bits loss in the data stream this communication protocol recovers losses bits. In the similar case an USB device causes computer to freeze.

6.3  What are advantages of LAN communication?
  • The LAN connector isolates the electrical connection between your PC and your LAN oscilloscope. A common cause of ground loops is thus effectively eliminated;
  • LAN communication has a galvanic isolation. It protects your computer against surges;
  • The great advantage of the LAN and the Wi-Fi connections is the great common mode rejection. Magnetic filtering minimizes static discharge noise, magnetic fields and radio frequency interference.

6.4  What power supply do I need for my CarScope Plus/LAN/Pro?
Power sources that can be used are vehicle battery or a 2.5mm DC plug external AC/DC power supply adapter.

6.5  How to connect CarScope Pro (Wi-Fi) to the Windows?
Open the CarScope program and go to Help → How To Connect → CarScope PRO.

6.6  How to check whether CarScope Pro is properly connected in Windows?
Power on the CarScope Pro (Wi-Fi) device and wait until the red LED goes off. Green led should be blinking. Go to the task bar (next to the clock) and press on Wi-Fi connections icon and you will see the CarScope-xx Wi-Fi network where “xx” are last characters of the serial number. They are unique for each device. Try to connect to the CarScope Pro Wi-Fi network. If connection is ok, a “limited access” label will appear.
If all above mentioned is ok you should have in mind that Windows 10 doesn’t have the Microsoft .Net Framework 3.5 embedded. See “How to install .Net Framework 3.5 on Windows 10?”.

6.7  How to connect CarScope PLUS/LAN (wired version) to the Windows?
Open the CarScope program and go to Help → How to Connect → CarScope LAN or Help → How To Connect → CarScope PLUS.

6.8  “CONNECT” button is not active?
If the oscilloscope is CarScope Pro (Wi-Fi), check if wireless connection between CarScope Pro and the Windows is established.
If the oscilloscope is CarScope LAN or Plus, make sure LAN cable is connected properly and device is powered on. If you don’t use a static IP address, you’ll have to wait more.

6.9  “START” button is not active?
Check if the CarScope device has been properly connected with program before that.

6.10  The following message appears /CarScope Pro/:
“Reading of the new calibration data has failed”.
What should I do?
Please reduce the distance between CarScope Pro (Wi-Fi) and the PC and try again.

6.11  Is it possible to use the computer that is running the program at the same time for internet?
This is not a good idea.

6.12  It takes too long to give computer an IP address. With static IP address everything is ok, but although I want to have internet?
Internet on the wired LAN adapter and CarScope Pro on the Wi-Fi adapter.
CarScope LAN or PLUS on the wired LAN adapter and internet on the Wi-Fi adapter.
Set several static IP addresses and do not use dynamic IP addresses. The first for garage's router, second for the home router and the third for CarScope Pro, LAN or PLUS.

6.13  Is there any plan to go to a more modern Wi-Fi, such as 802.11n?802.11n is a high speed network protocol. Such high speed is not necessary for the needs of automotive diagnostics.

7.1  Automotive-specific menus are not active?
To access the automotive-specificmenus you must have a CarScope device connected with the program.

7.2  What are the specs for frequency and voltage min/max?
See the Specifications section on the product page you have interest in.

7.3  Can I measure currents with an oscilloscope?
Yes, by using additional optional current clamps.

7.4  Can measured voltages be displayed in a digital meter like MIN/MAX/AVG way?
By using the measurement markers you can view only the max and the min value of the signal. You can’t calculate the average value.

7.5  Can I measure AC voltage and in what voltage range?
Yes, the voltage range is ±20V without attenuator, ±200V with 10:1 attenuator and ±400V with 20:1 attenuator.

7.6  Will the 600 Amp current clamps allow doing a quick cylinder compression test/comparison in relation one to another, according to the current draw during cranking?
Yes, the main purpose of a CA-600 current clamp is to do of relative compression test.

7.7  Can I test all injector types directly and if not, how to do this?
You have to use 10:1 or 20:1 attenuator on each oscilloscope input when viewing signals from automotive injectors. The reason is because every electromagnetic injector has an inductance which causes inductive spikes up to 60V depending on the type of the injector. When testing diesel common rail or petrol piezo injectors, driving voltage goes up to 170V depending on the injector being tested. Each oscilloscope input has an input range of 20V and that’s why you need an attenuator at each used input.

7.8  Can I have custom scale in degrees?
It's not possible to overlay a 0-360 or 0-720 time reference marker to indicate a full engine cycle for say crank or cam trigger traces at this moment. There are future plans for that option as a frame in an additional layer in which you will be able to adjust the reference marker.

7.9  What is the maximum record length for waveform movies?
In the current version of the program maximum record length in clipboard is 200 screens.

7.10  Why when I’m looking a saved signal changing the time base is not possible?
It is not possible, because if we add this option we have to invent new signal values ​​between already received measurements points from the CarScope device.

8.1  Are CarScope oscilloscopes suitable for CAN bus logic levels visualization?
CAN bus uses a differential signal, and the signal on one line should be a coincident mirror image of the data on the other line.  Both Wi-Fi (CarScope Pro) and LAN (CarScope LAN) oscilloscopes can visualize CAN network signals except those over 100kHz (high speed CAN) due to the low sampling frequency. It’s important to note that it is unwise to test the CAN bus signals with an oscilloscope as they are not periodical signals! CAN bus signals have to be tested with a CAN bus analyzer. So both Wi-Fi (CarScope Pro) and LAN (CarScope LAN) oscilloscopes are not suitable for "testing" CAN signals. Our new oscilloscope CarScope PLUS is suitable for viewing ("testing") the signal and confirm its presence!

8.2  Will the CarScope be able to display a Flexray bus?
Using of an automotive oscilloscope for this purpose is useless.

What are the basic accessories that come in the kit when you buy a CarScope?
Go to Accessories section.

10.1  What is the shipping time?
All orders placed will be processed and shipped within 2-3 business days, unless otherwise noted. Please remember that we are not responsible for lost or stolen packages. Packages sometimes do get lost in the mail, and we have no way to track your order down, unless it was shipped via DHL, UPS, FedEx and etc. Sometimes "lost" packages are held by Customs. If you haven't received your package within 15 business days, you can do inquire about your package at your local Customs office.

10.2  How much the delivery will cost me?
Please email us for specific delivery charges on any products you are interested in, stating your full deliveries address.

10.3  Shipping to the EU?
We usually use reliable overland couriers. Shipping time is usually 7 days directly to your door.

10.4  Shipping to the rest of the world?
We usually use UPS, FedEx. Shipping time is usually 4 days and It depends on local customs services.

10.5  If there is a distributor in my country, can I buy directly from you?
We do not send directly to the countries where we have our distributor.