PicoScope 6424E Oscilloscope + Accessories - Review

Table of contents

RoadTest: PicoScope 6424E Oscilloscope + Accessories

Author: cmelement14

Creation date:

Evaluation Type: Test Equipment

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: N/A

What were the biggest problems encountered?: Lacking programmer's guide for PicoScope 6000E series is the biggest problem for my road test. When I try to evaluate PicoScope's Labview and Matlab examples, neither worked out of box. Labview examples does exist for 6000E series but it doesn't work. I had to make some changes to get it partially working. However, without programmer's guide, it's hard to make it fully work. For Matlab, there's no examples for 6000E series at all. I briefly tried to modify examples for 6000 series, but realized even the instrument driver doesn't support 6000E series.

Detailed Review:

Introduction

First of all, I am grateful for being selected for this PicoScope 6424E Oscilloscope + Accessories roadtest. Really appreciate Pico Technology for providing such a great PC oscilloscope - PicoScope 6424E for this roadtest. Thanks also go to element14 community and [mention:55e535b498a841ed8f2949266bc56dc3:e9ed411860ed4f2ba0265705b8793d05] for organizing the roadtest.
Working from home becomes a new normal. As an engineer and hobbyist maker, having a compact measurement/test equipment on my home office desk becomes necessary. In this road test, I will evaluate Pico Technology's PicoScope 6424E and see if it's good fit. PicoScope 6424E is an all-in-one instrument including mixed signal oscilloscope, logical analyzer, spectrum analyzer, arbitrary waveform and functional generator, and serial decoder. Comparing to traditional low end to middle level oscilloscope, PicoScope 6424E has all following advantages: excellent portability,  best-in-class performance, unique FlexRes flexible-resolution, ultra-deep memory, all-in-one compactness, built-in all-included serial decoder, free lifetime software update, unlimited extensibility through PicoSDK, etc. In addition, this road test also includes the evaluation of Pico Technology's PQ215 probe holder kit.

 

Unboxing & First Impression

 

The road test material came within two cardboard boxes. Because of shipment mistake, I received 6403E first in one of the two boxes. After we reported the problem, Pico Technology sent the correct model 6424E very soon and I sent the 6403E back. The following two videos show the unboxing process of two boxes (i.e., 6424E and MSO pods/probe positioner kit).

Unboxing Videos

  

 

Unboxing Photos

Unfortunately, the videos don't clearly show the road test materials so I took lots of photos. To avoid cluttering this review, I uploaded those photos in the following blogs. If you're interested, please check out the links below.

PicoScope 6424E Oscilloscope Photos

TA369 MSO Pod Photos

PQ215 Probe Positioner Kit Photos

 

Carrying Case

The 6424E oscilloscope is packed in a very sturdy carry case which you can easily put more than 20 lbs weight on top of it and the case wouldn't have any noticeable distortion (as shown below). All equipment is protected by pretty thick surrounding foam which makes me confident that this oscilloscope package is well protected from rough shipment and future carrying and movement.

Size and Portability

The content in the package looks high quality stuff. They are well designed and manufactured. The 6424E oscilloscope itself is measured roughly 9.5"x7.5"x2.5" and it occupies much less desk space comparing to a traditional oscilloscope having the similar specification and performance. The oscilloscope is covered by rigid aluminum case which provides good protection to the internal components. It's also very good for internal heat dissipation with the help of the built-in fan.

 

Fan Noise

The noise from the built-in fan is definitely audible but it's acceptable in my opinion. It's maximum 41dBA from 1 foot away. In the normal working environment, the noise level shouldn't bother you much unless you are in a very quite environment.


 

Probe

The oscilloscope package came with 4x P2056 500MHz passive probes. Not like some cheap passive probes, they are reasonably high quality probes as shown below (with color coding rings installed).

 

The probe came with 2x spare spring tips and 2x solid tips. Changing tip is pretty easy process as shown in the pictures below. Just use a pair of needle nose pliers to grab the tip and lightly pull out the old tip, then grab a new tip and insert it into the tip hole. To make sure the tip have a complete contact with the probe, you may want to carefully press the tip against a hard surface, but don't use too much force and press it slowly, otherwise, you may damage the tip by accident.

In addition to a regular 15cm-long ground lead, each probe also came with a short ground spring. It is very useful for high frequency measurement because it can form a much smaller ground loop than a regular ground lead can do.

Each probe also came with a black insulation cap which could be very helpful in the situation that the test point is closely surrounded by components with exposed pins.

To get the best measurement results, each probe should be fine-tuned for a specific oscilloscope channel and should be always used with the same channel all the time. The match between the probe and the channel is based on the match of the color marked on the channel and the color of color code ring installed on each probe. Before the first measurement using a probe, a low frequency (LF) compensation calibration should be conducted by hooking up the probe to the calibration output on the oscilloscope's front panel with (picture on the left) or without (picture on the right) ground connection.

 

The adjustable component is a variable capacitor embedded inside the probe. On the top of the capacitor, there's a round opening where you can insert the trimmer tool. Unlike many other probes having variable capacitor with a slot head, this probe's variable capacitor has a Philips head. However, the trimmer tool is a slot screwdriver. I found slightly inconvenient to align them together in order to do the calibration.

The adjustment range is pretty small. Thus the fine tune should be conducted very slowly. The adjustment should not require much force so don't over stress the capacitor. Otherwise it may damage the probe.

To make the compensation process easy, I turn off all channels other than the one under calibration. After hooking up the probe to the CAL output, use PicoScope 6's Auto Setup capability to get a stable waveform (with Auto trigger on the correct channel).

In addition, you can also enable 20MHz bandwidth limit on the channel. Also use the maximum resolution enhancement capability as shown below.

 

All four probes in the package have very good match with four channels and it really doesn't need any further compensation (as shown below). Since I randomly pick up probe for each channel, that means both oscilloscopes and probes are well manufactured with very good precision.

If for some reason the probe is over compensated (as shown below) or under compensated, slowly rotate the trimmer tool until the waveform looks like the one above.

MSO Pod

The road test contains two sets of TA369 8-channel MSO pods (see TA369 MSO Pod Photos ). The pod itself looks high quality but its accessories look like low end stuff.

For example, the pin grabbers/hooks (black & white hooks) look like cheap stuff comparing to most traditional oscilloscope accessories (grey hook).

The pin hook is too bulky and you may not be able to use them to connect to consecutive pins on an IC as shown in the picture below. On the right hand side, we can connect 5 good hooks on 5 consecutive pins. However, on the left hand side, with this cheap hooks, we can only connect to 3 out of 5 consecutive pins.

The interface cable between the oscilloscope and the pod seems pretty rigid but may not be flexible enough. That means you may have to give more desk space for digital measurement such as logical analysis and/or digital serial decoding.

 

Miscellaneous

The AC/DC adapter within the package is a really good one which is qualified for medical device applications. The oscilloscope package includes a hard copy manual which I don't think it's necessary. Nowadays, almost all documentation is in digital format. This manual doesn't really add much benefit other than adding more cost and weight.

 

PQ215 Probe Holder Kit

The road test also includes a probe positioner kit which consists of an aluminum base plate, four PCB holders and four probe holders (see PQ215 Probe Positioner Kit Photos). After briefly playing with the kit, I really like this kit.

Firmly Holding PCB Boards

The kit can firmly hold all kinds of PCB boards I have. The board sizes range from 0.5"x0.5" to 8"x6". Here are the Photos - PQ215 Probe Positioner Kit Holding PCB Boards. The PCB holders grab all PCBs so firmly that I don't think they will move or drop by accident. You have to use quite lot force to intentionally remove them. To confirm how strong the PCB holders can grab the boards, I used my hand grabbing the board and lift both the board and base plate in vertical position. Neither the board nor the base plate moved a bit at all. A few photos can demonstrate that.

Prepare PCB Holder

To avoid the holders' metal part shorting circuits on PCB boards, two insulation washers should be installed on each PCB holder. First, peel off the cover of the adhesive as shown below.

Pull the spring-loaded sleeve downwards, open the slot on the washer and slide it around the pin. Make sure one washer's adhesive side upwards and the other one downwards. Pull and quickly release the spring-loaded sleeve a few times to make sure the washers firmly attached to the metal part.

 

 

 

Highlights of PicoScope 6424E



Probe Auto Detection

 

Like most modern oscilloscopes, 6424E can automatically detect Pico Tech's probes. If we connect the standard P2056 probe, it will automatically detect it as x10 probe.

On the other hand, if we connect a coax cable, it will use x1 probe by default since it cannot automatically identify the probe. If x1 probe is an inappropriate option for your probe, you can either choose either an equivalent built-in probe or create a new type of probe.

 

 

FlexRate Resolution

 

6424E provides a flexible choice between sampling rate and resolution through the technology called FlexRate. For fast digital signals, you can use 8-bit high speed, low resolution option, but for high resolution measurement, you can choose 12-bit resolution. And 10-bit is good balance between sampling rate and high resolution. To see the resolution difference, we use 8, 10 and 12 bit resolution individually to sample the same 1V, 1KHz sine wave generated by the built-in signal generator.

8-bit resolution:

10-bit resolution:

12-bit resolution:

From 8 bit to 12 bit resolution, we can see the waveforms getting smoother and smoother. If the difference isn't too significant to you, let's zoom in and the difference will become obvious.

8-bit resolution zoom-in:

10-bit resolution zoom-in:

12-bit resolution zoom-in:

Labview Example

 

In my opinion, one of the biggest advantages of PC oscilloscope comparing to traditional oscilloscope is the extensibility and flexibility to interface with other systems. PicoScope is especially good at this aspect. They usually provide drivers for common test and design platform such as Labview & Matlab. It also provides lots of examples in various programming languages. Its SDK basically provides unlimited capability to customize your test and measurement system. You can easily integrate PicoScope to your test system no matter it's a Labview based solution or in-house automated test system programmed in C, C#, VB, Matlab, Python or other languages.

 

6000E is a pretty new series. I don't expect the support as good as other Pico series, but I still want to try to see if I can get it work on this road test device - 6424E. It turns out the Labview support for 6000E is available on its github page (https://github.com/picotech/picosdk-ni-labview-examples ). However, the example code doesn't work out of box. I had to make some changes to make it work.

 

The first problem is the interfaces between two blocks doesn't match.

I have to add a couple of new elements to fix the mismatch.

The second problem is described below.

When I double click on the error, it shows the error came from the highlighted component below.

However, when I open the component configuration and it seems not match with the error description mentioned above.

Even it doesn't make sense, I reconfigured it and that error did go away.

Then I tried to connect the CAL output to channel A with P2056 probe and started running the Labview example. The example code tried to control the oscilloscope (I heard the relay's click sound) but eventually it failed and showed the following error message.

I had to step into the code and did some debugging with the help of SDK header file. It turns out channel enumeration for 6000E series is different from 6000 series. It's offset by 32. That's why I add an adder with a constant 32 for the channel parameter.

   

Finally, I got it work but I believe this sample code still has lots of problems. Every time I adjust a setting, the code crashes. Anyways, I think Pico Technology has lot of work to do on this. They need to fix problems in this example code and also create a few more examples. One way to speed up this is to encourage the customers contribute to the github repositories.

 

Matlab Example

I also tried Matlab examples for 6000 series on 6424E and obviously it didn't work. I tried to modify the code, but I found out even the Matlab instrument driver (.mdd) for 6000E series doesn't exist. I realize it will take some time which I don't have at this moment. Maybe later, when I have a little bit time and Pico Technology hasn't created one yet by then, I can try to get it done.

 

No Programmer's Guide for 6000E Series

When I worked on Labview and Matlab examples, I realized there's no update of programmer's guide for 6000E series. I think this should be a high priority task for Pico Technology. It seems the APIs for 6000E series have significant updates from the 6000 series. Without programmer's guide, users will be very difficult to integrate and extend its capability.

 


Serial Decoding

 

PS6424E has very powerful serial decoding capability. To test it, I set up a kit as shown below. In this set up, serial decoding on both analog channels and MSO channels have been tested. Both analog channels and MSO channels are sampling the same set of SPI interface signals. To facilitate the test, I created the software with an infinite loop where the SPI master sends a byte each time and the slave sends it back after it receives it. The SPI baud rate is 1 Mbps. The byte value sent by the master infinitely loops between 0x00 and 0xFF incrementally. Since the slave sends its received byte back to the master, we expect the byte value on MOSI always greater than the value on MISO by one except when the byte value loops from 0xFF back to 0x00.

Let's take a look at the demo video first followed by a brief explanation. In the video, the most top part shows the decoded data on MSO D0 channel (samples on MOSI pin). Next, it's the decoded data on MSO D1 channel (samples on MISO pin). The next four waveforms below show the four analog channels (Channel A, B, C and D in order). They are sampling the SPI interface's 4 pins in the following order: MOSI (Master out slave in), MISO (Master in slave out), SCLK (SPI clock) and SS (SPI chip selection). Please note, the first two waveforms also contain decoded data. In the middle of the screen, it shows four MSO pod channels (D0 to D3). They are sampling the same 4 pins just like the four analog channels do. At the bottom of the screen, the table shows all decoded data in the buffer.

 

 

In the video, I showed how easily we can zoom in and out, search the data buffer, double click on a specific byte in the table to locate and zoom into the associated waveform.

The use of serial decoding is pretty straight forward and easy to set up. The screenshot below shows what is required to set up serial decoding on analog channels.

The screenshot below shows what is required to set up serial decoding on MSO channels. Please note I renamed D0 ~ D3 with more meaningful names.

To get stable waveform display, we need to choose a good trigger source and trigger method. In my case, I choose triggering on a falling edge on chip selection pin. PicoScope offers lots of triggering methods which are shown in the screenshot below.

 

 

 

PicoScope 6424E in Practice

 

This demo shows how to use 6424E's two channels to sample a pair of differential CAN signals and decode CAN data. Sometimes you don't have direct access to CAN controller's digital pins but only have access to a pair of CAN wires as shown below. If you want to trouble-shoot CAN bus problem in this situation, you can hook up your oscilloscope's two channel to two CAN wires. They are differential signals. If you create a subtract math channel (subtract one channel from the other), you will get the CAN data on that math channel.

As shown in the screenshot below, we have channel A connected to CAN High and B channel to CAN Low. The purple channel is the match channel A-B. Even both channel A and B have floating ground and also have big noise on them, the math channel has pretty clean digital signal which can be used for decoding CAN data (data shown in the table).

The screenshot below is a zoom-in waveform for one CAN message highlighted in the table.

 

 

Conclusion

I really like PicoScope 6424E's high quality, high performance, great capability and portability. It's a really good cost effective solution given the factors that multiple devices in one package, free software and SDK for integration and extensibility. Since 6000E is a new series, hope Pico Technology will update the programmer's guide and code examples as soon as possible so customers can maximize the benefit brought by the device.

 

I also like the PQ215 probe positioning kit. It really holds PCB very firmly. I am pretty sure you can do some soldering work while it holds your PCB board. With the great flexibility of probe holders plus the help of a little bit gravity and spring-loaded probe tip, the probes can have pretty precisely and firmly contact with test points and components' pins.

 

Last but not least, I would like to thank Pico Technology and Element14 community again for this great road test. Also thank you for reading the review. If you have any specific things or ideas that you want to try on 6424E, please leave your comments below. I will keep updating this thread when I have more time to play with it.

Anonymous
  • Rare that I have seen a representative of the vendor post on a RoadTest. It may happen more often than I am aware of.

     

    If I can say one thing about my experience with the PicoScope 6424E Oscilloscope + Accessories is that I would recommend the purchase of the equipment. You are getting value for money.

     

    Thank you CB , and the support team at PicoScope for providing the E14 Community the opportunity to RoadTest your equipment. It provides opportunities many of us will rarely get the chance to participate in and receive a far greater benefit.

  • Carl from Pico here. Many thanks for your review, overall very positive but with some issues raised that are duly noted.

     

    The LabVIEW bug will be fixed and the MATLAB driver and progs manual are in progress and will be available soon,

     

    Thanks,

    Carl.

  • Good work on the review!

     

    Very interesting - I never realised that this Picoscope essentially uses the same probes as the Rohde & Schwarz RTM3004 I reviewed before, just with different labelling. The design is quite distinctive, as is the choice of colour-coded channel rings.

     

    - Gough

  • Great review CM. I particularly liked the probe setup, External software and CAN decode testing.

     

    I think you have given the vendor some good feedback to consider for product development.

  • Nice, The serial decoding feature is something new to me. It seems invaluable for troubleshooting.

  • Nice road test report.

     

    DAB