USB- 232/4 and USB- 485/4 hangs

[TiTou]

Right, so I'd like to understand how my USB-232/4 can be "working properly" and only have 2 ports according to the Device mananger.

 

Message Edited by TiTou on 04-20-2010 03:54 PM

[ranjini]

It ('device working properly') shows the status of Communications port 3 (COM6), and not the status of  NI USB-232/4. As per this ur two ports are deleted / disbaled. i too have observed this.

I strongly believe that some noise of some kind is entering in ur system. May I know, what all devices/field instruments u have connected through NI USB 232/4? 

[TiTou]

A device that measure the noise made by a mechanical watch (http://www.witschi.com/e/produkte/?sub=1&cat=&id=10) and two maxon motors (http://test.maxonmotor.com/docsx/Download/catalog_2005/Pdf/05_159_e.pdf).

Do you think that could generate enough noise to screw a converter that cost twice as much as an Exsys one (http://www.exsys.ch/download/catalog/ex_1334HM.pdf) ?

[TiTou]

I'm sorry if I sound a bit grouchy but I'm having hard time with this device 😞

[ranjini]

Ok :p. U can check whether any kind of noise from neighbouring rooms/labs. no other clues, i have.

But anyway thanks for the info on  http://www.exsys.ch/download/catalog/ex_1334HM.pdf

[Wayne.C]

TiTou,

I don't blame you for being grouchy.  What kind of controller is being used to drive the dc motors?  Does the pc in question interface to the motor controllers as well?

[TiTou]

Hi Wayne,

Yes, the we use EPOS library to control the motors through RS232.

[Wayne.C]

TiTou,

Best guess is that noise source is the motor drives.  As a test I would try to optically isolate 232 connection used for motor control.

[TiTou]

I changed the NI USB - 232/4 for the Exsys converter 2 weeks ago and still had no crash.. finger crossed.

At least if the issue came from electrical noise, then the Exsys is much more tolerant to it than the NI one... and it's half the price!

[CWolf]

Hello,

I hope your application is up and running properly with no crashes.  I would like to know some more about the issues that you were having with the NI USB-232 converter.   Did changing out the device prevent the issues that you were seeing with your built in serial port?  Also, how often was the situation occuring where you could not see two of the ports on your card?  What type of computer are you using?  Any additional information that you could provide would be very useful so we can try to replicate this issue through testing here.  We are constantly trying to improve our testing and the robustness of our cards, and will look into this issue.  

Have a great day!

-Christina W.

Applications Engineer