Baudrate setting with CVI runtime for Linux

[Martin_Manger]

Hello folks,

I have a problem concerning the baudrate setting with the CVI runtime for Linux.

I want to communicate with a device which has a USB-to-serial chip from FTDI. The driver for this device is already included in the kernel (openSUSE 11.1, kernel 2.6.27.23-0.1-default i686).

I can use a terminal program (HTerm 0.8.1beta) to open the serial port at /dev/ttyUSB0 and can set all the baudrates the device supports (38400, 115200, 921600) and the communication is working perfectly.

Now I take the serial example from NI and run it under Windows. I expanded it to support 921600 baud, and it works fine. Then I try to run this sample under Linux (I expanded it to open /dev/ttyUSB0), but it only works for 38400 baud. If I try to set 115200 or 921600 baud then I get RS232 error -14 (invalid baud rate).

It would be nice if there is anybody who can give me a suggestion what I have to do to get 921600 baud working.

Best regards,

Martin

[Marco_Brauner]

Hi Martin,

are you running Linux and windows on the same machine with the same serial port?

Could it be that your serial port isn´t configured for 11520 in the Linux-distro you are using?

The usually supported baudrates of VISA for Linux are:

Standard baud rates supported by most serial ports:
	110	300
	600	1200
	2400	4800
	9600	14400
	19200	28800
	38400	56000
	57600	115200

On my end everything is working fine. I was running the "basic serial.vi" on both the Linux and the Windows System @ 115200Baud.

So there should be something with your serial settings I guess.

Marco Brauner NIG

[Martin_Manger]

Hi,

I think there was a little misunderstanding. I am not using LabVIEW but LabWindows/CVI with the Linux Run-Time Engine. And I'm not using VISA calls but the RS232 library with OpenComConfig, ComRd etc.

Windows and Linux are on the same PC. And the serial port (which is a virtual serial port because it's a USB-device with FTDI-chip) must be able to communicate up to 921600 in the Linux-distro as I can use the Linux terminal program HTerm with this baudrate to successfully communicate with the device.

Regards,

Martin

[nickb]

Hello Martin,

Actually, you appear to have run into a known issue with the CVI Run-Time Module for Linux.  Attached below is a patch that should resolve the situation for you.  The readme file explains how to install the patch.  Please let me know if you have any questions or trouble with the patch.

Thanks, and sorry for the inconvenience!

NickB

National Instruments  

[Marco_Brauner]

Hi Martin,

yes, you are right. I was too fast going to the Linux-machine right beside my PC, connecting them with a serial cable and

running the quick visa-test, which was working well. 

Ok, thank you Nick for providing the patch. And I also would be available if there are further issues to test.

regards

Marco Brauner NIG

[Martin_Manger · Accepted solution]

Hi NickB,

the patch did it!

Thank you very much.

Best regards,

Martin