Hello Element14 community!

Few days ago, I received my reward from Experimenting with Supercapacitors. My participation in this contest I summed up in final blog Final Blog: Supercapacitor Backup Storage for Low-Power Compact Sensors about one month ago.

Multicomp Pro MP720025 4ch 100MHz 1Gsps Oscilloscope

It is very nice oscilloscope. It is not my first oscilloscope. My first oscilloscope was table oscilloscope which I received as part of different Element14 activity and described it here: MP720644 Multicomp Pro Tablet Oscilloscope. The new oscilloscope has very similar analog performance. Both has 100 Mhz bandwidth and 1Gsps sample rate. But the new unit has 4 channels while my previous tablet oscilloscope has only 2. The other benefit for me is bigger size with more hardware buttons and knobs. It makes intensive works much more seamless.

Oscilloscope box contained power cord, USB cable, printed quick start guide, CD with software and two packs of two probes. Probe kits are referred as OW3100. It seems that MP720025 is rebranded Owon oscilloscope like I thought previously in case of MP720644. It seems that MP720025 is rebranded Owon XDS3104E.

Testing with Element14 Test Signal

I of course tested it with my DIY arbitrary waveform showing Element14 logo on display. In previous case I was limited by two channels. Look for example at E letter. I was unable to make gap in it with just two channels:

Now with 4-channel I can generate element14 signal more precisely. Even single channel remained free, so I used it for better triggering:

I had to upgrade my tool for generating patters and trigger signal and also change device for generating it. Originally, I used microcontroller (STM32L5 if I remember correctly) which has only 2 channels. Now, I used MAX5715 DAC breakout which supports 4-channels and for timing and fast data transfers I used Cypress microcontroller which has nice advanced DMA which allowed me to make transmission accurate and almost fully hardware accelerated with almost no jitter.

Some thoughts after first day of using

The oscilloscope is big upgrade for me. With my previous tablet oscilloscope I was mostly limited by 2-channels. For example, when I was troubleshooting my Mini Solar Powered Wireless Temperature Sensor as part of Experimenting with Supercapacitors I was facing issue. I was analysing behaviour of sensor when device charges enough to power up regulator, but it immediately fails. I was monitoring voltage on supercapacitor and voltage output of regulator. Because it uses advanced chip it has several voltage lines and I was interested in monitoring system voltage also, but with my table oscilloscope I was able to monitor only two at the same time. So, I had to monitor it separately and hope that I see the same situation. Now with 4-ch scope it should be much better and it is also good for analysing more than 2-wire digital buses.

The other issue which I had tablet oscilloscope is that it has due to size constraints very limited user interface any many tasks are outsourced to touch screen. I frequently do unintended action just because I forged to switch some mode button or select active channel and consecutively, I changed something different than I needed. My new MP720025 has also touch screen but almost all tasks are possible to do with mechanical knobs and buttons.

Both scopes have very similar firmware and UI, but there are still differences. For example, menu is in case of tablet MP720644 better, I think. It seems that in case of MP720644 it was optimized for using with touch screen and on MP720025 it is optimized for using with buttons. MP720644 has all options available in grid, while in case of bench MP720025 you need to click next button for seeing more options. But MP720025 menu can be controlled completely without touching touch screen.

Even equivalent features slightly differ. For example, bench MP720025 has in “Save” menu option for making screenshots with white background color (feature is referred as “Ink Saver”, but tablet MP720644 has no such feature. When enabled, it makes screenshot on white background:

In opposition tablet MP720644 has DAQ and DMM option. Bench MP720025 has physical DAQ button, but after clicking, it shows “DAQ(Data Acquisition) is optional”. Waveform and DMM which are in manual mentioned as optional are not present. Manual seems to be copy pasted from Owon manual including descriptions of features which are not present on Multicomp units. In manual available at Farnell/Newark store, all screenshot figures contain Owon logo. :D In printed manual, logo was properly censored. It is also confusing in the manual because control panel description shows and describes different buttons than photo shows. Photos are correct.

MP720025 supports decoding the same digital protocols as MP720644 but I do not know how to configure it. The only difference is that in MP720644 there is UART, but in MP72025 there is RS232 decoder. This maybe explains why UART decoding did not worked to me in case of MP720025 because it most probably checks voltage levels also and I did not used right RS232 high voltages. On the other side, I still do not know how to use it this feature properly. I tried UART/RS232 and SPI decoders, but both without success. The configuration is split to trigger and decode menu and both are slightly misleading to me. For example, when configured for decoding SPI, it allows to select only two inputs referred as SDA and SCL. I originally thought that this is restriction of 2-ch scopes, but 4-ch MP720025 has the same menu. In my opinion decoders do not work on these scopes, but maybe I just did not understand it. My best result is that I received wrong results from RS232 decoder.

Measurements and cursors work on both scopes the same and I use them very frequently. On bench MP720025 configuration is much seamless because of physical knobs.

Triggers configuration is the same, but bench MP720025 allows to sync with mains. Tablet MP720644 do not support it because even when connected to mains using charger, because it is powered from DC. Bench MP720025 also has force button and physical knob which is not shared with other functions.

At last, fan in bench MP7200275 is more silent than in MP720644. Most probably because it is easier to handle air flow in bigger case.

Summary

It is nice scope, I think. While there are some minor issues and I can’t clearly say that bench version of Multicomp oscilloscope is better than cheaper tablet version in all ways, for me it will be primary scope now. Mostly because of 4 channels and better control interface. In opposition I will sometime still use tablet oscilloscope because it has some features which are disabled in bench MP720025 and is powered from battery (it is isolated from mains).

What happened to other part of Experimenting with Supercapacitors Runner Up Reward?

The last question is: what happened to other part of reward. Careful readers of Experimenting with Supercapacitors may know that runner up prize consisted of oscilloscope and GoPro camera. I did not receive camera. Because of very tight results in this competition, I decided to ask Element14 staff to split my reward and send GoPro camera to dougw instead of me. Dougw as part of competition provided very good blogs and shown interesting techniques as well as very well build supercap meter which in my opinion is the most complexly built meter as far as we have seen in Experimenting with Supercapacitors. He received only few points less than me. For this reason, I decide to give half of my reward to him. I think the split of second place reward to make third place reward in this competition make sense.