Bug in Read binary serial Visa5.2.0 Macosx

[PaulRijk]

When reading binary data the property node "Serial Settings:Number of Bytes at Serial Port" shows a wrong number of bytes when one or more bytes has the value of xFF. For each byte on the bus containing xFF the #bytes is incremented by one. So when the bytes 10,20,30,255,112 are sent to the computer, LabVIEW's #bytes shows 6 bytes. So reading 6 bytes will time-out after which 5 bytes are received with the values as sent. When the bytes 10,20,30,254,112 were sent, everything is OK. This was done on MacBookPro MacOsX10.7.5 and VISA5.2.0 LabVIEW2009SP1/2012 Also reproduced it with Mac OS X 10.6.8 / LabVIEW 8.5.1 / VISA 5.20 seems to be a VISA bug/feature Regards, Paul

[Corné_Westeneng_NINL]

Hi,

I Have read your forumpost and I have a couple of questions.

Did you measure the same problem with an older version of NI VISA?

Can you please send me an example VI so I can reproduce the incorrect behaviour?

Best regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

[PaulRijk]

Hi Corné,

I did not try to un-install Visa and install an older version because I don't want to disturb my own work.

With the attached VI "Heen&weerTestSerial-V1.vi" you can simulate the problem by installing it on 2 computers ( e.g. a Mac and a PC) and let it run on both at the same time while the computers are connected using a Null-modem cable.

While running change the data array of the sender in that way that one of the bytes show FF (255).

The problem will appear when the Mac is receiving and the PC is sending 1 or more bytes containing xFF

Paul Rijkers

[Corné_Westeneng_NINL]

Hi Paul,

Sorry for the late response. 

Today I did a test with your VI on 2 Windows 7 laptops. 

I'm not able to reproduce the incorrect bahavior.

In your situation you use MACos but we do not have a MACos system available.

I have a couple of questions:

- Have you allready performed a test on 2 Windows pc's instead of MAC?

- Can you see any incorrect behavior with NI I/O trace?

You find the latest serial driver + NI I/O trace bellow

NI serial 3.9

http://joule.ni.com/nidu/cds/view/p/id/3621/lang/en 

Performing a Good NI I/O Trace Capture for Debugging/Troubleshooting

http://digital.ni.com/public.nsf/allkb/282C5D41E2BA04F2862574BA007803B9?OpenDocument

Best regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

[rolfk]

It's a known problem and only affects MacOS and Linux versions of VISA.

As I have tried to explain in that thread, while it is a bug in Bytes at Serial Port, using that property in serial port communication is almost always the wrong thing to do (and likely the problem why this bug hasn't been noticed much earlier).

[Corné_Westeneng_NINL]

Hi Paul,

I saw you have a discussion about your question also on a other forum.

Do you still need support from our side?

Regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

[rolfk]

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@cornewesteneng wrote:

Hi Paul,

I saw you have a discussion about your question also on a other forum.

Do you still need support from our side?

Regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

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Maybe you could add the CAR number for this bug report. Eventhough I think use of Bytes at Serial Port in any type of instrument control is in fact the wrong thing to do, this is clearly a bug that should be tracked and hopefully fixed in the future.

[PaulRijk]

Hi Corné,

As Rolf already stated, this is a bug which should be solved.

Regards,

Paul

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@cornewesteneng wrote:

Hi Paul,

I saw you have a discussion about your question also on a other forum.

Do you still need support from our side?

Regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

---

[Corné_Westeneng_NINL]

Hello Paul,

At the moment I'm in contact with my colleague's in Amerika about this issue.

I almost have all the necessary information.

What version of Labview do you have on your Windows System? 

Regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

[PaulRijk]

Hello Corné,

This issue is about a VISA error on MacOsX, not on Windows.

I used LabVIEW version 2009SP1,  but it was also seen by others with LV8.5.

I think it is the VISA-version that matters, more than the LabVIEW version.

Regards,

Paul Rijkers

@cornewesteneng wrote:

Hello Paul,

At the moment I'm in contact with my colleague's in Amerika about this issue.

I almost have all the necessary information.

What version of Labview do you have on your Windows System? 

Regards,

Corné Westeneng

Applications Engineer

NI-Netherlands

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