Comments/Questions re Touchpanel

[AnthonV]

Hi, excuse the long post but I am evaluating the TPC-2012 as we are thinking of replacing our current (non-NI) touch panel with this unit.  From our point of view there are several good reasons for doing this mainly as the rest of our system also run LabVIEW and integration will be much simpler using the TPC.

During the past week I’ve put the TPC through many tests evaluating the reliability, ease of use and ease of programming, data throughput, TCPIP packet handling and GUI abilities.  Overall it seems to be a good product but I have the following issues which might be because of my inexperience with it, because of a bug or it might be a future feature – if anybody could comment on these it will help me a lot.

*** User input:

1) There seems to be no way to bring up an alpha-numeric keypad (CE native or user-created) when the user clicks inside a string or numeric control.  The only events that are caught on these controls are ‘Key Down’ and ‘Value Change’ but neither triggers when the control receives the focus.  I suppose one could place a transparent button on top of the control and catch its ‘value change’ or have a ‘Change Value’ button next to the control, but neither is a very elegant solution.

2) It is not possible to pop up a subVI’s front panel as a floating window, it has to fill the whole screen (as a dialog). 

3) Boolean buttons (I’ve only seen this on pop-up dialog windows) do not work correctly if the mechanical action is ‘switch when released’ or ‘latch when released’.  Even though the front panel shows the button is pressed, the diagram does not react to it and continues to use the old value.  After several presses it works.

4) Most finger-on-screen events are missed on dialog windows.  The first press always works (ie button turns dark), but subsequent presses only have a 1-in-10 chance of being picked up.

5) An enum control’s value can only be changed using the up-down buttons, if you want to select from a list rather use the combo box.

*** Data display

1) Graphs only supports lines.  Scatter plots are not possible neither are bar-graphs.

2) The circular white background on a gauge is not centred around the needle or numbers.  It is slightly offset to the top-left.

3) When an X-Y graph is updated it displays as it draws the lines.  It would be better if it created the image in the background and then put it on the front panel once completed.  This is particularly annoying when there are many datapoints to plot.

*** Other

1) The ‘TCPIP listen’ vi loads the processor a lot.  It is significantly more efficient to use the ‘Create Listener’ with the ‘Wait on Listener’ functions (other application loops run 5 times faster).

2) Even though I added the exe to the list of applications to run at startup (using the ‘National Instruments Configurator’), it did not start after a reboot.  Double-clicking on the exe in the same location starts it, and adding another exe (e.g. control panel) starts that exe after a reboot.

By the way I’m using 8.5.1.

[AnthonV]

After a bit of digging I found answers to some of my own questions, but for the remaining ones above I would still appreciate any comments.

> User Input 1 (see above):
Poll the 'keyfocus' property of all the input numeric and string controls and call your keypad vi if the property is true (see the attached image for an example of this).

> User Input 3 and 4
This behaviour was caused by the 'lock front panel until event completes' option in the calling vi's event handler.  This was a bit tricky to diagnose as events still reached the popup window (although only about 1 in 10 of them).  So if you pop up a window on the press of a button using an event handler be sure to untick this.

> User Input 5
This is described in the help file as a known behaviour.

[Kaddatz]

Your observations are valid.  We recently invested in a number of TPC-2012's as HMI for our setup.  I had originally thought that the process of creating interfaces would be easy (being LabVIEW), but I guess I didn't research it as well as I should have.  I have repeatedly come across unsupported properties, idiosyncracies, and bugs which have required me to rewrite/rework my code.  One example:  I had a network-published shared variable of "custom" type that included a enum as part of a cluster.  This works fine for "regular" LabVIEW, but causes the TPC application to crash/hang.  It took a lot of troubleshooting to discover that it was necessary to split the enum out of the shared variable, into its own shared variable.  Another problem I've had, for which I have a support call into NI right now, is that I can't get ANY of the graphs support "real" time on the x-axis.  The waveform chart control updates incorrectly, adding 2-3 data points (presumably one for each component of the waveform?) on for each update cycle.  The XY graph doesn't support time along the x-axis when deployed, despite the fact that the VI looks OK on the development computer.  The waveform graph defaults to "Ignore waveform timestamp", and if you change the checkbox value, the x-axis changes scale to show time, but won't reflect the data.  (However, the data exists, since the cursors are able to report them).  The waveform graph example that is provided can be used to demonstrate that this doesn't work properly.

In summary, I find the TPC-2012 frustrating.  We invested in LabVIEW since it would eliminate the need to focus on "how" to do, and allow me to focus on "what" to do.  As a novice LabVIEW user, my experience has been extraordinary - the RT controller works fantastic and I've created some great interfaces for standard XP computers.  However, lately, much of my effort has been devoted to finding work-arounds for the idiosyncracies of Windows CE and Touchpanel module.  Hardware-wise, the TPC-2012 is fine.

Does NI offer the TPC-2012 with either XP or XPe OS's?  The documentation seems to indicate that the TPC-2012 supports either of these operating systems, but I've found nothing else regarding any performance hit that would occur if either were installed  (nor am I quite sure how to install the OS to the flash-drive - from the quick read I've had it seems either the flash drive OR a CD-rom can be connected, but not both).  I would be very interested in knowing more about XP or XPe on these units, as it would allow the installation/use of a "regular" LabVIEW EXE, which would eliminate the need for working with the touch-panel module and provide the full gamut of properties/controls/programming capability.  Since the TPC comes with drivers on the CD, the user would still be able to interface via "touch", making the difference transparent to them.

[AnthonV]

Hi Kaddatz. I'm sorry to hear of your frustrations.  I suspect that as this is still a new (and upcoming) product line all the issues we are experiencing will be sorted out in future versions and you are paying the price for being at the 'bleeding' edge. 

For a significant price increase you can go for one of the full-blown panel computers which will run XP.  However, I'm looking for something cheaper.

As I'm more of an old-school programmer by training I tend to avoid shared variables, especially with the RT, FPGA (and now Touch Panel) platforms.  I find that it is a lot more efficient to use a standard TCPIP messaging structure.  For instance I have a cRIO, CompactVision system and Touch Panel connected together with a ethernet switch and I'm using the Touch Panel to display images (apart from all the normal machine control and diagnostic information) from 3 cameras connected to the CompactVision. This is done at several frames a second.  Maybe it can be done with shared variables too, but I do not have experience with using it.

Coming back to the actual issue of the gaps you are seeing in the support for front panel controls and indicators (when compared to what you are used to on XP): I have no doubt it will eventually support all features we require (as 500MHz is not slow), but whether it will do it before my 30 day trial of the touch panel module expires I do not know.

[Kaddatz]

With reference to ***Other #2 (application startup):

The TPC Configurator method does not work for assigning a startup file, since the configurator only creates an "ini" file in the startup directory.  The actual VI remains in its original directory (typically "My Documents" if using TPC deployment option).  When the system reboots, the My Documents directory is erased (see http://digital.ni.com/public.nsf/allkb/15ED0B1496CCC65A8625730900752057), along with the file that you want to have startup.  The workaround is to use the File Explorer method as detailed in http://digital.ni.com/public.nsf/allkb/219F856644BDF9F78625713B006721A9.

[AnthonV]

Thanks I now have the application running at startup.

[StevenA]

AnthonV

As to 1) I'm finding that even if you use the native alpha-numeric "Input Panel" that LabVIEW does not recognize the input value.  That is, it shows up in the control, but the actual value on the wire is not updating... very strange behavior. 

Indeed there are many idiosyncracies wth the Touch Panel Module... I have been doing development on them since before the release of the Touch Panel Module (when you had to use PDA module)  In general I'm pretty happy with the end results, but the touch panel module projects can be a headach to develop.

[AnthonV]

Thanks for the feedback.  Luckily I seem to have the input keypad issues sorted out by using our own VI's.  Only snag is that they fill the whole screen (ie they do not float over your application as the native one does), but this does not seem to bother the end users.

My biggest headache has been the graphs as I had to develop my own x-y scatterplot using a picture control.  In the end it works well but it cost a bit of sweat to get there, and there will be the inevitable regular upgrades.

Anthon

[Stijn_Schacht]

Hello everybody,

I am also investigating the pro/cons of NI's touchpanel series on windows CE. So far my buglist goes on, the most important being:

1) numerical controls do not update when being entered with a keyboard

2) string controls do not update when being enterend with a keyboard (I do not see how else to update a string, so string controls simply do NOT work on touchpanels)

the above bugs only are present when you run two or more loops in parallel. If you do not whish to have these bugs, you have to write everything in one loop. This leads to messy code, since the multithreating mechanism of labview is a true benefit of using labview. Instead, touchpanels make you turn back 180° back to the early 70s with one single loop..

[Sorooshster]

Hey Stijn,

When you mean that the numerical controls and string controls don't update when entered with a keyboard, are you referring to the onscreen touch keyboard that Windows CE has or are you connecting a keyboard via USB?  Also, you are seeing both of those bugs only when you have two or more loops?  What kind of loops are they?  Just a standard while loop or does it work for a while loop or a for loop?  Thanks.