F190 Series Multi-function Oscilloscope Application Cases

1. Product Overview

Fluke's F190 series multi-purpose oscilloscope fully embodies the perfect combination of speed, performance and analytical capabilities. It has technical indicators that can only be found in high-end desktop oscilloscopes, and can provide 200MHz bandwidth, 2.5Gsps real-time sampling rate, and advanced memory and trigger functions; it is also rugged, compact, and battery-powered. Specifically, the F190 series also has the following functions and features:

1.

Dual channels at 60, 100 and 200MHz with real-time sampling rates up to 2.5Gsps; Connect-and-View, automatic trigger, full manual trigger mode and external trigger function; 27,500 points per channel in oscilloscope record mode; automatic capture and reproduction of 100 screens; 24 automatic waveform measurements; cursor reading, image magnification and real-time clock; 4-hour rechargeable NiMH battery; Class II l000V independent floating isolation channels; 5000-word true RMS multimeter and trend plotting paperless recorder.

Figure 1 High sampling rates provide the resolution required for detailed signal analysis

2. Multiple bandwidth options

With the choice of 100MHz and 60MHz models, you can enjoy the same advanced features without having to pay extra for extra bandwidth.

3. Really see all the details

With a maximum real-time sampling rate of 2.5Gsps and a resolution of 4OOps, you can really see what is happening. Two channels have independent digitizers, allowing you to acquire and analyze two waveforms simultaneously at maximum resolution and clarity. If an anomaly flashes on the screen, just press a "Replay" key to see it again.

Figure 2 Pulse width triggering makes it easy to find abnormal pulses

4. Deep memory for high-resolution oscillographic recording

Each channel can store 27,500 points, allowing up to 30 hours of high-resolution event recording, or static capture of fast pauses and glitches as low as 50ns. Continuous roll mode can also store events such as motion curves, UPS, power supply and motor start. 100X image magnification technology allows you to see the finest details. Dual channel 27,500 point records can also be stored for subsequent analysis.

Figure 3: 27,500-point oscillographic record storage and image magnification technology can maximize the observation of details

5. Advanced trigger modes

Flexibly select automatic and manual trigger modes to capture any signal. The touch-and-test function allows fast and easy multi-point testing. Manual modes include delay, video and pulse width triggering. A fully isolated external trigger channel synchronizes two input signals for fault detection of the time relationship between them.

6. Powerful analysis functions

For analysis of waveform oscilloscope recording and trend plotting, 24 automatic measurements, cursor readings, image magnification and real-time clock can be used to analyze directly on site or back in the office. Two records and 10 waveform screens can be stored and printed or downloaded to a computer.

7. Wider range from mV to kV

The F190 series has 3 independent floating isolation channels, each of which meets the safety certification of Category II 1000V and Category III 600V. The standard probe covers a wide range of applications from mV to kV, making the 190 oscilloscope an ideal test tool from microelectronics to electricity.

8. Multifunctional test tool

Like the industrial multi-function oscilloscope 123, the 190 series also integrates an oscilloscope, a multimeter, and a paperless recorder. The rechargeable hydride battery provides 4 hours of continuous operation. Charging time is only 4 hours. The power saving and automatic shutdown functions can even easily carry out a full day of work.

9. Automatic capture and reproduction of 100 screens

Press the "Replay" key in time to track previous events. Under normal circumstances, the instrument continuously records the latest 100 screens. Each time a new screen is captured, the oldest screen is automatically refreshed. The latest 100 screens can be frozen at any time and observed by scrolling one screen at a time or continuously replayed as a dynamic graph. Cursor readings can also be used for further analysis. Up to 100 specific events can be captured using advanced triggering capabilities. Dual-channel 100 screen captures with independent time stamps can be stored, reproduced or downloaded to a PC.

2. Application Cases

Since the F190 series has so many features and functions, let's take a look at some of its typical application cases.

1. Maintenance of CNC machine tools

At present, the CNC rate of machining equipment has reached more than 90%, and the application of CNC machine tools (CNC machining center, CNC lathe, CNC mirror bed, CNC wire cutting, CNC EDM, etc.) is becoming more and more widespread. The debugging and maintenance of machine tool CNC systems account for more than 65% of the debugging and maintenance of machine tools. Choosing appropriate test equipment is the key to improving the work efficiency of debugging and maintenance personnel.

In the development and production stages of CNC systems, medium and high-end oscilloscopes and even logic analyzers will be used, but these devices have special requirements for test instruments in the online debugging and on-site debugging stages of production, as well as on-site maintenance and repair stages.

In actual applications, CNC systems have power-off protection functions, that is, when the power grid loses power, it is discovered in time and the on-site data is stored within the time that the system power supply can be maintained. The actual circuit has no problem during the experiment, but the feedback in actual use is that the circuit sometimes does not work. In addition, the CNC system will suddenly crash during normal operation. What exactly is the cause? Through analysis, engineers believe that it is caused by abnormal signals from the power grid. In order to prove this judgment, this signal must be captured by instruments.

Using an analog oscilloscope, it is not possible to observe the signals of the power grid and the circuit at the same time, nor can it capture occasional single signals. Using Fluke's handheld oscilloscope can solve this problem very well. Because the two channels of the oscilloscope are completely isolated, we can directly use the two channels of the oscilloscope to observe the signals of the power grid and the circuit. Because the signal is occasional and the trigger condition is unclear, the waveform recording method can be selected to monitor the signal. When the CNC system crashes, stop waveform recording, analyze the recorded waveform, and find that the drop of the power grid signal causes the system to mistake it for a power-off signal, and the system cannot work according to the normal program at this time, causing the crash. The failure of the power-off protection circuit has no direct relationship with the power grid.

The channel isolation and waveform recording functions solve the user's specific problems, and the 100-frame waveform playback function is very useful for users to capture waveforms such as drop signals. The standard configuration probe can directly measure the power grid waveform, saving the user the cost of purchasing a high-voltage probe. Battery power supply and portable functions are very suitable for on-site commissioning and maintenance of CNC systems.

2. UPS installation and maintenance

UPS is one of the key devices to ensure the normal operation of equipment in telecommunications systems. With the increasing requirements for communication quality, higher requirements are also put forward for the performance of UPS. Therefore, testing before and after UPS commissioning has become a necessary task.

The traditional method is to use an oscilloscope to observe the waveforms of some signals, and then use a power meter and a multimeter to measure other electrical parameters. As more and more users attach great importance to the dynamic indicators of UPS and require the instrument to be able to perform fast measurements on site, traditional methods can no longer meet the application requirements. Fluke199/200MHz oscilloscope can easily solve a series of test and measurement tasks that are difficult to achieve with traditional methods. The specific instructions are as follows:

First, use the deep memory and oscilloscope recorder of Fluke 199 to capture the dynamic processes of UPS loading, power-on, switching to backup power, etc. The steady-state process is required to be less than 20ms when UPS is loaded, and the stabilization time is required to be less than 5ms when switching to backup power. Since the Fluke 199 oscilloscope can record continuous waveforms for up to 11s at a time base of 10ms under the oscilloscope recorder function, the entire process of dynamic signal generation can be fully recorded, and then the image magnification and cursor reading and other analysis functions can be used to observe and read its stabilization time. The above measurements can also be conveniently performed using the external trigger and playback functions of Fluke 199.

Then use the oscilloscope playback function to record and analyze multiple single events. Intermittent spike signals may appear during the startup process of UPS. Using the pulse trigger mode, the instrument will automatically capture up to 100 trigger events, so that various abnormal events that occur during the startup process can be fully recorded. Then use the playback function key to call out the captured screen and analyze it with image magnification and cursor readings.

For example: power and power factor, current and phase, and at the same time, harmonic analysis can be achieved using software, which can save the inconvenience of carrying a large number of instruments to the field.

3. Automatic monitoring and maintenance of power system dispatching

Whether in research and development or in actual work, we will need to analyze some rapidly changing signals. The whole process of this type of signal is very short, but it contains rich information. When capturing this type of signal, we often lose the head of the signal. The F190 series has made a useful contribution to revealing the true face of this type of signal.

The F190 series oscilloscope always automatically stores the waveform in a very deep memory without user intervention. The oscilloscope's 2×27.5K sampling point memory is cylindrical in structure and can store 100 waveforms of channels A and B, ensuring that the user always has a history of waveform signals in hand.

The "playback" automatic memory function is particularly useful for analyzing the fast-changing signals mentioned above. The following is an example of a field test in a certain urban power supply bureau.

The dispatching room of the urban power supply bureau monitors the remote transmission units (RTUs) distributed in the distribution stations throughout the city through the dispatching automation system RD800, as shown in Figure 4.

Figure 4 Power supply bureau dispatching automation system

The 4~20mA signal sent by the transmitter is converted into a digital signal, and then the digital signal is converted into an analog signal and modulated onto a sine wave. It is transmitted from the RTU to the pre-processing system through an audio cable or an optical cable; the pre-processing system demodulates through pre-processing such as modulation and demodulation, and then converts it into a digital signal through analog-to-digital conversion and sends it to the background control system for processing. In this way, the dispatcher can observe the situation in each distribution station in the main control room. Once a power outage or other event occurs, the dispatcher can respond in the shortest time. In order to ensure the normal progress of industrial and agricultural production and the normal life of the people, this process is not allowed to be interrupted. In order to ensure the normal operation of the entire process, the dispatcher needs to monitor the frequency change and peak-to-peak value of the sine modulated wave from time to time. If the frequency deviates from the allowable range, the RTU will not send the signal from the cable. In addition, when the signal is transmitted in the cable, it is easy to induce noise due to grounding. These noise levels are large enough, and the pre-processing system will not collide with the demodulated information and cause communication interruption. Because this signal came too fast, when the dispatcher reacted and pressed the "Hold" key, half of the waveform had passed, leaving only the second half. With the F190 series oscilloscope, the dispatcher can press the "playback" button after the entire event occurs to easily reproduce the entire process. Using powerful analysis functions such as cursors and waveform magnification, the dispatcher can quickly determine the frequency changes and peak-to-peak voltage values ​​of the signal, and can store some waveforms as needed. Since desktop oscilloscopes do not have this function, users are very satisfied with the performance of the F190 product.