Speed and Precision: In last month’s newsletter we introduced the new PicoScope 4226 and 4227, our 6th generation of high-resolution oscilloscopes. These 12-bit scopes have bandwidths of 50 and 100 MHz and sampling rates of 125 and 250 MS/s. One of the other features that may have sparked your interest is serial data decoding, so we're going to look at that in more detail this month.
CAN and I²C: Two serial formats are currently supported: CAN Bus and I²C. We know that many users would like additional formats, so we are working to extend this list. Serial decoding is integrated into the main PicoScope display, so there is no need to learn a new layout and controls. When you select Serial Decoding from the Tools menu, PicoScope asks you to select which channel to decode. CAN decoding requires a single channel, while I²C requires two channels for data and clock. You can either specify the data rate or let PicoScope auto-detect it.
Waveform and Table displays: The 32-megasample buffer of the PicoScope 4226 and 4227 is large enough to capture thousands of data packets or frames with accurate timing. The decoded data is then displayed underneath the waveform, so you can monitor the signal quality at the same time as the data. Errors are shown as red data values. For maximum information, you can view the data in a table that describes every frame or packet in detail. If too much information is displayed, you can filter the data to show only the packets of interest. You can also tell PicoScope wait for a specified data value in a specified field before beginning decoding.
Other Scopes: If you don’t have a PicoScope 4226 or 4227, don’t worry: PicoScope’s serial decoding feature works on all our USB scopes. You just need to make sure that the scope has enough memory to capture the data packets of interest with enough time resolution. PicoScope will tell you if there are not enough samples to decode the data.
We recently made it much easier to save-on-trigger (save each waveform to a file as soon as it is captured) inPicoScope. This is useful for saving data from unattended experiments or long-term tests. Just follow these steps:
Set up PicoScope to trigger on your signal. “Repeat” trigger mode is best for this procedure.
Open the Tools menu and select Alarms.
In the Alarms dialog, set the Event option to “Capture”.
Edit the Action and change it to “Save Current Waveform”.
In the File box, browse to a suitable directory and enter a filename. Bear in mind that PicoScope will save a new file on every trigger event, so make sure that the chosen directory has enough free space.
Don’t forget to tick the Enable Alarm box at the bottom of the dialog.
Click OK to return to PicoScope. Click the Start button, and PicoScope will start saving-on-trigger.
The Alarms feature is extremely flexible, and as well as saving files it can sound an audible alarm or execute a program, triggered by a variety of events.
The latest update to the software for the PicoScope 9000 Sampling Oscilloscopes allows you to control the scope from your own program. The software can now act as an ActiveX COM server, allowing any program to send commands to it using a standard Windows protocol. This makes the PicoScope 9000 Series scopes ideal for production-test environments where multiple scopes need to be controlled from a single PC, or where automated tests need to be run. You can download a free SDK that includes example programs and documentation.
Our dedicated recruitment website, pico.jobs, has been running since 2007. In that short time it has grown to provide 28% of our job applications, and enabled us to tap into a wider source of talent including local students seeking work experience, the Engineering department of nearby Cambridge University, and other applicants worldwide.
Why are we telling you this? Because we want you to know that Pico Technology is always looking for new talent, whether you are an analog or digital designer (particularly if you have an interest in oscilloscopes), software engineer or technical support expert. Even if one of our advertised positions (see our regular Jobs section below) doesn’t match your abilities, we still want to hear from you if you think you have something to offer us. Pico Technology is growing all the time, and we may be looking for someone just like you.
Here is another question that cropped up recently on our support forum:
Q. I have just bought a PicoLog 1216 and a transducer with 4-2 0mA output. However, the PicoLog manual only refers to measurements from 0 to 2.5 VDC. How I can make the PicoLog 1216 take 4-20 mA input?
A. It is really easy to convert to 4-20 mA input on the PicoLog 1000 series. You simply add a 120 ohm resistor across the input and 0 V of the channel in question. If you use the small terminal board (see User’s Guide) supplied with the PicoLog 1216, there are positions to add 0805 surface mount resistors in the relevant places. The 4 mA current will then generate 480 mV at the input and 20 mA will generate 2.4 volts. To convert these voltages into properly scaled readings, you must use the “Scaling” option in PicoLog. If, for instance, the output of the transducer is 0% at 4 mA and 100% at 20 mA, you would set up a look-up table to equate 480(mV) to 0(%) and 2400(mV) to 100(%).
When in the “PicoLog 1216 Measurements” dialog box, click “Edit” for the channel in question.
In the “PicoLog 1216 Edit measurement” box, click “Options”.
In the “Parameter options” box, tick “Use Parameter Formatting” and set “Units” to “%”, “Formatting” to your own preference and then click “Scaling”.
In the “Parameter Scaling” box, set “Scaling method” to “Table look-up”.
In the blank box, you can now enter pairs of “Raw” and “Scaled” readings. In this case the table looks like:
Please visit Pico Exhibitions for the latest list of exhibitions and trade shows that Pico and its representatives will be attending.
Thanks to our continuing success and growth Pico are always seeking talented people to join our company.
Please visit https://jobs.picotech.com/ to see our current vacancies. We look forward to hearing from you!
Our latest software releases are available as free downloads. To check which release you are using, start the software and select Help > About.
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