Instrument Control (GPIB, Serial, VISA, IVI)

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How to get a baudrate of 921600 with visaconf

Hi,
I am using visa 4.2 and have to get a baud rate of 92160 in order to communicate with a wavelength meter. I tested it with windows and everythign looks fine there. But I am using a linux machine to actually run my experiment. I can't get the data over thge serial port. I am using a USB to serial driver (silabs cp2103) and this driver supports 921600. Also on the wavelength site the USB chip is from silabs and hence supports the high baud rate. When I try to set a static local serial port in order to communicate with my device the choice of baud rates stops at 460800.
Is tehre any workaround ro get the required 921600 bauds?
According to the knowledge base baud rates up to 921600 should be supported since visa 3.5.
Thanks
Thomas
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Message 1 of 19
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Hi,

In MAX I can set the baudrate to 921600 and validate is successfully with the hardware that supports such a baudrate.

Version 4.2 Visa and 4.3 MAX.

Did you try it in MAX ?

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Message 2 of 19
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Thanks for the fast response.
As far as I know there is no max for linux or am I wrong?
With my windows setup (virtual machine hence the exact same hardware) I have no problem to connect. Its just that with visaconf the scroll down menu does not allow for 921600
Thomas
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Message 3 of 19
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It's not a standard baudrate, so it will not show in menu's. I don't know what language you'r using, but in LV I simply feed the serial configuration VI with the baudrate I want.
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Message 4 of 19
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Hm, according to the silicon labs USB/serial driver it is a standard baud rate, but I am certainly not experienced in this kind of problem ..... so you must be right. The problem with these USB to serial drivers is that even if you install them you also have to tell LV that there is a new local serial port. The only way so far is using the visaconf environment which only allows to set the baus via pull down menu. Somewhere I have to tell LB that the serial port binding is in /dev/ttyUSB0. If there is something else for visa under linux where I can freely set the baud, that would be great. But perhaps tehre is no such thing. The weird thing is that visa does support this rate as stated in following knowledge base article:
http://digital.ni.com/public.nsf/allkb/D37754FFA24F7C3F86256706005B9BE7
OK it says only some serial ports support these baud rates ..... but my port does support it as the driver can handle it, the USB chip on the wavelength meter as well and hence the only problem must then be visa .....
Hm clearly there is somethig I am not getting here
Thanks
Thomas
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Message 5 of 19
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Is it not possible to use the 'standard' serial functions with Linux as with windows ?
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You mean like serial.vi ? yes that's possible. But I have a program for which I have to define the port and I connect via USB, hence as the port is not recognized on the fly as it is with windows, I first have to create a static local serial port for which I have to tell LB the binding file and for which I have no freedom to choose whatever baud rate I want. There must be a way to create this local serial port without the preset baud rates but i don't know how
Thomas
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Message 7 of 19
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I don't know anything about the combination Linux and LV, so I can't help you there  Smiley Sad
Do you have LV on a windows PC ? If yes can you create VI's that you can use with LV on Linux ?
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Message 8 of 19
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Oh yes, usually my vi's run in both OS's with no problems. Its just this baud rate problem that came up because of the requirment of the wavemeter.
Anyway thanks a lot for your help so far
Cheers
Thomas
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Message 9 of 19
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OK good luck, if you need further help just call.....
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Message 10 of 19
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