Tektronix TBS 1202B-EDU


Another CRO Digital Oscilloscope. I need to stop referring to them as CROs. In my defense, the thing that was, until recently, taking up all available space on my desk really was a CRO.


The Tektronix TBS 1202B-EDU Digital Oscilloscope is small, lightweight, has some buttons and knobs and does stuff. Stuff you expect a Digital Oscilloscope to do. No more counting divisions and making little calculations on the back of the scrap of paper to work out a phase shift. It does it all for you. It is what you expect from a Digital Oscilloscope.


So what is the purpose of the TBS 1202B-EDU ?


This Oscilloscope is aimed at the Educational Market (therefore “EDU”) and the key part of this is the Courseware software


Using the software that comes with the oscilloscope you can create a “course” and then add “labs” and in each lab, create an overview and step-by-step procedures. Once you have created the course and labs you can package them, copy them to a memory stick and load them into the oscilloscope through a front panel USB slot.


Students using the oscilloscope press the “course” button and get access to the course material, step through to their lab and can begin work. If they have brought a memory stick, they can plug it into the oscilloscope and as they perform the experiments, record the results using a combination of the 'Step #' and the “Save Result” button. At the completion of the lab they use a “Report” button which generates some html to wrap all the saved data. There is no “eject USB” so just wait until the saving message goes away and unplug the memory stick.


The process of recording the results happens as a screen capture so you need to have your measurements visible on screen when the capture occurs.

 

copy of Tek007.jpg

It is important to change the step number on each save or you will overwrite earlier results. It would be nice to be able to just press “Save Result” and have a time stamped screen shot but the purpose of the EDU version is to operate in an educational environment and the screen-shots are recorded as they relate to particular steps in the current process.


Using the Courseware


There is a small learning curve to using the Courseware. If you already have documents with your lab overview, procedures and step-by-step instructions, you can cut and paste a lot of your information from your existing files. Some you cannot, a brief list is below.


Text: cut and paste – some reformatting required.


Equations: there is an equation editor built in. The equation editor may not have the characters or symbols you want so check it first. The list of symbols might appear short but the list can be expanded using the button in the corner. This might seem obvious but on my computer the button was labelled in what I presumed was Chinese (language was set to English). If the equation editor is too much bother and you already have the equation in another document, treat it as an image.


Images: you cannot cut and paste images from existing documents, BUT the program includes a little screen-shot tool. If you have your source document immediately behind the Courseware editor, then click the screen grabber icon and automatically the document behind the current window will appear with a screen grab tool. Select the area of the image and click 'done'. The image will be copied into your Courseware document. Very easy, very quick.


Experiment and make sure your images are not too large for the oscilloscope screen.


Overall operation of the Courseware.


For the first couple of uses of the Courseware the operation may seem a little odd but not too odd. At completion of editing a lab and after saving the lab, you close the lab editor and the package / course editor is still sitting behind. You add the lab to the course and then rebuild the package and export it to your memory stick.


Note: you can also export labs as a PDF. Do it now while you still have the Courseware package open.


At the oscilloscope, plug in the memory stick and press the utility button. Work through the menus and upload the course. If you were doing this for a whole lab, by the time you had loaded the first half dozen oscilloscopes you would have the loading process down pat.


Student use of prepared courses:

course_buttons.jpg

Students start the oscilloscope and press “Course” to see the course menu. They use the menu buttons to select a course and then use the multi-purpose knob to scroll to a lab and select it. Once they find the lab they can use the menu buttons to work through the overview and the procedures, saving oscilloscope screen shots as they go.

 

This is reasonably simple and should be usable for students from upper primary through to university level students.

 

In this touchscreen age you might find yourself continually pressing the on-screen button and then mentally hitting yourself with a stick for falling into that trap – again.




Online Courses:

Courses and Labs are available on-line at tek.com. You can download these and incorporate them in your courses if you desire. You can also upload courses to tek.com.


Courseware Pros:

Reasonably easy to use after the first few runs.

Reasonably quick to convert existing documents to Courseware documents.

Creates a html package of the course.

Can export PDF versions of labs.

Other labs available onine.

 

Courseware Cons:

These are minor quibbles that you will quickly adapt to.

Doesn't like spaces in labs names but just says “invalid”.

Doesn't have a lower-case π (pi) so some equations look a little odd.

Equation editor “show more” button was labelled in Chinese while the language set to English.

You might initially create images that don't fit the screen.


General Observations & Issues:


The oscilloscope came with a CD with manuals, two probes, a power cord and some little zip-lock packets of spares. Grab these, put them is a slightly larger zip lock bag and sticky-tape them to the bottom of the oscilloscope. In three-years time you will know where to find them.


Out of the box – if you are familiar with Digital Oscilloscopes, you will find your way around fairly quickly.


The CD was a problem as I was using a netbook when the oscilloscope arrived. I used another computer and copied the material to a memory stick and then realised the second problem, all my PCs were Linux but the files on the disk were Windows. The instructions came packaged in a MS compressed html format (.chm). It turned out I had  a chm reader installed ( I had used one a year ago but forgotten). Like most CDs all the instructions were in PDF format anyway so it didn't matter. Follow the directory-tree to the language of your choice and the PDFs are inside.


The Courseware software runs on Windows and under WINE on Linux. I wasn't aware of any issues using it under WINE. I imagine it can run on MACs through a virtual PC.


The oscilloscope has a back panel Type B USB socket (the large square one) . The Oscilloscope can be connected to a printer or to a PC.


VISA (Instrument Automation)

To connect to a PC requires a PC running some VISA compliant software. For windows PCs this is Tektronix's OpenChoice software and it can be downloaded from tek.com (you need to create a login on tek.com). This program did not list this oscilloscope, or its near relative the TBS1000, but it did appear to work with this oscilloscope.


The download was 391 MegaBytes and took much longer than it should have. The tek.com website appeared non-responsive at times and occasionally served up error pages or timed out. I had noticed this on a previous recent occasion so it might be symptomatic of the web site.


You will also need to download the programmers manual (search for TBS1000 Programmer's Manual).


tek.bmp

 

If you want you can write programs in Python to control and interrogate your instruments. See the following section on VISA on Linux. A similar process applies to Windows.


NOTE: Also see this post on the element14 community:

http://www.element14.com/community/groups/test-and-measurement/blog/2013/10/06/controlling-oscilloscopes-from-your-pc


The above software should load the necessary drivers as recommended in the blog post above. You can then control your oscilloscope using Octave.


VISA on LINUX.


I didn't get this running (yet) but basically there are two steps.


(1) Go to National Instruments and create a login and then download their NI-VISA install files. These are available for MAC and Linux. Install them. You only need the libraries.


(2) Go to your package manager and install PyVISA (Python VISA wrapper). Alternatively go direct to pyvisa and download the latest version.


I got stuck on step (1) because I use Ubuntu and the installers are for SUSE, Redhat and Scientific Linux. I did get most the way to installing the libraries but I didn't have time to go back and search out the issues. I was using the RPM package manager which wasn't really aware of what I already had installed so it coughed and spluttered. I may try again using the Debian Alien installation process and see how It goes.


The PyVISA just installed with no issues. There are various help pages and little snippets of python code on the web. If you are not a python coder (I'm not) then I think the most important thing to remember is that python is space sensitive on indenting. Python coders may disagree on the importance of this but hey, what do I know?  If you are using code examples from the web make sure you have the right versions of Python and pyvisa. From what I read it seemed that I needed to be using Python 2.7 and then I had to be aware that the code snippets related to pyvisa 1.4 not the latest 1.5.


OVERALL


It is an Oscilloscope, it works.

Many students use their phones or tablets to read Lab instructions as they work but I think this instrument with the ability to embed course notes has a place in Labs. Not all students have smart phones and the ability to flick back and forward between instructions and measuring seems attractive. It wasn't intrusive and certainly deals with the "I forgot to print the lab notes" disease.


The tek.com website was a bit slow and annoying at times but I did get to the relevant pages:

  •       OpenChoice communications software (only needed for comms with a computer)
  •       Programmer's Manual (for use with above software)
  •       Courseware Lab packages (shared by other users)


The Oscilloscope User Manual and the Courseware User Manual came on the disk.


The Courseware software worked well and after a little trial and error and referring to the manual, this was quite easy to use and with a bit more practice I could get quite quick at using this. I would probably continue to generate my lab guides using a word processor because of the ability to create images and equations. The time to convert a document to Courseware is not that large.