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RFID reader stops scanning after an hour

Posted: Mon Oct 19, 2020 4:41 am
by JonPerkinsWds
My company is in the final stages of developing a retail product which uses the 1024_0B device. We predict that we will sell hundreds of these devices per year, each on using a single Phidgets RFID device. The software is written in C# as a Win32 app using .NET Core 2.1 and the Phidgets NuGet package and it will only run on Windows 10 (with all hibernation settings disabled), although I have got to the point where I am thinking the problem is at a lower level than the C# code for reasons I will explain.

There is a point in the software where the user can scan an RFID card which we know works with the 1024_0B. The software calls the RFID Open() function, waits for a second, and then sets AntennaEnabled to true. There is an immediate call afterwards to query the AntennaEnabled property to verify is OK. It also turns on the external light on DigitalChannel 1 to give the visible feedback that it is ready to go.

For about an hour or so the software is able to read correctly, via the Tag event, and I cannot get it to fail during this time window. However, the ability to get a tag reading fails after an hour or so and then I can't get it to work at all. I can still successfully turn the light on and off, and the AntennaEnabled and Attached properties still report true. I have tried permutations of opening and closing the connection and setting the AntennaEnabled property more often but none of these combinations make a difference. NB I never actually turn the AntennaEnabled property to false, depeing upon the context I either process the results of the Tag event or ignore it.

The thing that makes me wonder if something is happening at a deeper level is that I can tidily close the Win32 app and restart it and the device still fails to read (Attached property still reports true). However, if I pull out the USB cable and then reconnect the Tag function works correctly again.

Have you seen this problem before, and are you able to offer any suggestions as to why this is happening? I would be very grateful for help, I have spent quite a few days continually coming back to this and it is now delaying the initial launch of our product.

With thanks,

Jon Perkins

Re: RFID reader stops scanning after an hour

Posted: Tue Oct 20, 2020 3:47 pm
by Patrick
Do you see this issue if you open the 1024 from the Phidgets control panel and leave it running for a long time?

Do you see any errors in the Phidgets log (do you have logging enabled)?

Do you see the same issues on multiple 1024s?

-Patrick

Re: RFID reader stops scanning after an hour

Posted: Mon Oct 26, 2020 7:22 am
by JonPerkinsWds
Hello Patrick,

My apologies for the delay in responding, I am working from home during the lockdown and it took a while to get hold of some additional devices from our main stock to further the tests. Also, I realise now I hadn't noticed that I needed to tick the "Notify me when a reply is posted", so I did not know a reply was waiting.

I do also see this problem purely from the Phidgets Control Panel app. When I first start the program from fresh the device scans OK. After about an hour this becomes unavailable, although I still have control over both LEDs and the Digital Output. I have tried toggling the "AntennaEnabled" checkbox but it makes no difference.

I just created a log file - verbose so still rather large, and I attach it here. I actually saw the fault occur while I was typing this, the "RFID Reader/Writer" window closed and re-opened. The log file shows the problem occur at the very end of the file.

I do see the same error on multiple 1024s.

HOWEVER, I have since discovered that I am so far only seeing this on my one dedicated test laptop (a 2.5 year old Microsoft Surface Book 2 15"). I cannot replicate it on five other Windows 10 computers that I have tried it on (inc 3 laptops), so it seems to be an issue with the computer. I have checked all the hibernation and power settings and they are all disabled.

I also notice that the Phidgets Control Panel will not start at all once the reader has gone into this non-read mode, which is usually after an hour or so. There is no sign of a crashed version of the program in the Task Viewer. The only way to get it working again is to physically remove the USB cable and reattach it, at which point everything is reset.

I feel a lot easier that I can only see the fault happening on one computer so I am inclined to start rolling out a few units to beta testers for a wider sample, so I intend to leave it at this for now. The fact that your Control Panel app also has the same issue reassures me that there is nothing specifically wrong in my own code. If you do have any suggestions then I would be pleased to hear them, but hopefully this is a one off and I will hope to move on.

Thanks,

Jon

Re: RFID reader stops scanning after an hour

Posted: Mon Oct 26, 2020 9:26 am
by Patrick
Some Googling shows lots of complaints about USB on the Surface Books - maybe see if there are any firmware/bios updates available. From the log - it looks like USB reads just start failing.

-Patrick

Re: RFID reader stops scanning after an hour

Posted: Mon Oct 26, 2020 10:03 am
by JonPerkinsWds
Thank you very much Patrick