BAUD RATE

[PETRAN]

Hello!
I have noticed that, in LabVIEW 6, the maximum BAUD RATE (Serial Settings-->Serial Baud Rate) I can enter in a property node is 115200 bits/sec. That number is not sufficient for my application. Is there any way to increase that number?
Does LabVIEW 7 support higher Baud Rates?

Thank you in advance!!

[Conseils]

Using Labview 6.1 and 7.1 under Windows XP I have tested baud rate parameters to 921600 baud with a USB serial device which purports to support such rates.

I have no exernal hardware that supports this rate, but could conceveivably connect two USB serial devices together, I think cabling and noise could start to be interesting at such baud rates.

In principal therefore I would anticipate that it is your hardware that does not support a higher baud rate than 115200.

[PETRAN]

no it is not the problem with my hardware (I attach the specific .vi to see for yourself that it has nothing to do with my external device)
my external device is an image sensor that sends a pixel stream in the serial port RS-232 and via my .vi, I capture those pixels and I convert them into a 2-D array (288x384).
Use an external device of your own choice that extracts bytes and try setting a standardized Baud Rate more than 115200 bps. you will find out that you will receive an error message that has to do with the baud rate in the property node(values such as 115200,57600,38400,19200,9600 or lower are OK.______the problem is with higher values). NOTE that for the time being I use only the RS-232.
I would be grateful if you could find a solution for my problem.
Thank you very much!

[Conseils]

Sorry I was a little ambigous with the 'hardware' term, I should have perhaps been clearer.

I suggest that it could be the P.C. hardware not the external hardware that is incapable of supporting the desired baud rate.

Anyway testing your code with my serial interface at the highest baud rate (921600) seemed to configure OK.

[PETRAN]

!!!!!!! that can't be true!! i mean that i have also tested my .vi code in one of the computers of the laboratory at my university and it keeps sending the error message. To be clearer, the error message is as follows:
"Error -1073807330 occured at Property Node (arg 1) in Camera 3.vi

Possible reasons:

VISA: (Hex 0xBFFF001E) The specified state of the attribute is not valid, or is not supported as defined by the resource."

Does it ring a bell?

I repeat that this message is appearing when I set a higher number than 115200 bits/sec in the front panel of my vi.
Also, I have only a simple 9-pin cable that connects the camera with COM1 port of my computer.
Does it have to do with the settings of WinXP that are related with the specific Port?

Sorry for being a pest but I don't know what to do. Thanks again

[Conseils]

Persistance is a virtue and will stand you in good stead......

I attach a picture to demonstrate the point..

A thousand words of value perhaps?

[altenbach]

If you use the PC serial port, it might well be limited to what you are seeing. Do you know the type of UART on the motherboard?
Go to the device manager and look at the properties of the serial port. What is the highest baud rate listed?

Conseils is using a USB to serial adapeter that natively supports higher speeds. Maybe you should get one of those yourself ;). What baud rates are supported by your image sensor?

[PETRAN]

the highest baud rate listed in the device manager (Serial port properties) is 128000 bits/sec (of course LabVIEW accepts only standardized values, so the highest value I can enter in the property node is 115200 bits/sec). My image sensor sends 1 byte (pixel) every 139 nsec!!! But I can decrease the pixel rate to 1 byte(pixel) every 9 usec. Anyway, I hope that with the Serial to USB adaptor, I will be able to set higher Baud Rates in LabVIEW that will be valid. What do you think??
Thanks for your advice!!!

[Conseils]

It is true of the more traditional P.C. hardware that baud rates were limited to 115200. Usually the connecting devices available such as modems also had this speed as their upper limit. With analogue PSTN modems, higher speeds were not required as it was not practicle to send data over standard telephone wires over about 56Kbps anyway, so after compression and handshake overhead, you ended up at 115200. There was also consideration of cabling and connectors and standrards to take into account. It seemed fast at the time as I recall 🙂

With the introduction of USB RS232 interface devices, the availability of higher throughputs has become more common place.

The specific device that I tested is available from the following location:-
http://rswww.com
The part numbers are: -
497-9124 4 port device


I am sure there are others, there have been some comments in this forum on longterm stability of such solutions and you might wish to read up about these if this is a concern for your project.

A hardware driver will probably need to be installed for which administrator privalidges will be required.

Please note
I also confirmed testing on Windows 2000 under Labview 6.1 through to 7.1 and the USB to RS232 devices appear to be recognised satisfactorily. Note that I have not actually sent any data at these higher rates - yet. Although the device mentioned has performed continously for over 1000 hours at 9600 baud without issue, in a harsh industrial environment.

[Brian_Beal]

I am using a PCI serial card. It is 485, not 232, though. I am running it at 500K. This is just to reinforce that the speed is hardware dependant, and also, I select any speed I want. I am not limited to any specific speeds.