finding baud rate from unknown instrument details

[hanumeshbujji]

Hello every one....iam wirking with one project but the problem is i have to interface a serial port  to pc....from an instrument but i dont know the serial parameters like baud rate..no of bits...so is there any method to find outfindind baud rate automatically....

[JÞB]

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@hanumeshbujji wrote:

Hello every one....iam wirking with one project but the problem is i have to interface a serial port  to pc....from an instrument but i dont know the serial parameters like baud rate..no of bits...so is there any method to find outfindind baud rate automatically....

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Yes, VISA provides auto-detection of baud rate on some operating systems.  It is a lot easier to read the manual of the remote device!  And,that does take a human developer!  (in theory -- a vi COULD be designed to read that document for you and implement the paramaters but, it would be harder than reading the few manuals for the devices you may be using) What is that thing on the other end of the port?

[Dennis_Knutson]

Jeff,

What auto-detection are you talking about? I'm not aware of anything that VISA can do with an instrument. The combinations of all the parameters makes it very impractical. The absence of any sort of standard commands or protocol like GPIB has make it impossible.

[JÞB]

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@Dennis_Knutson wrote:
Jeff,

What auto-detection are you talking about? I'm not aware of anything that VISA can do with an instrument. The combinations of all the parameters makes it very impractical. The absence of any sort of standard commands or protocol like GPIB has make it impossible.

Timing between machines is inexact.  Just get in the range of the Baud rate--- VISA adjusts for it (At least on''windows OS' kernels")  Its why the Baud rate input is a integer not an enum---- 

"RS" still stands for "Recommended Standard"  Hardware defines the transfer layer! ( As always!) The FW engineer on the device still has some input onto the interface.  Asking for the remote device name and manual is not asking too much.   

[billko]

I'd just go Google the manual.

This is like guessing the combo on a combination lock.

edit:

Or do you know what commands to send?  This makes it quite a bit easier, but still tedious.

[Dennis_Knutson]

Jeff,

That makes no sense, sorry. Work out of the number of combinations of baud rate, parity, stop bits, hand shaking, termination character, etc. Then make up a command to the instrument and wait for a response. Repeat.

[JÞB]

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@Dennis_Knutson wrote:
Jeff,

That makes no sense, sorry. Work out of the number of combinations of baud rate, parity, stop bits, hand shaking, termination character, etc. Then make up a command to the instrument and wait for a response. Repeat.

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No, Read and interpeate the various forms (and styles) of the maual documents... Perhaps write a search that finds some "Key" words ---then hope %95 of instrument developers can translate that to what is needed.   Like I said--- Easier to read the manuals by humans!

Spoiler

Untill there is an I-Manual standard that all engineers follow.

[Dennis_Knutson]

If you don't a manual and don't have any existing software that is communicating to the instrument, throw the instrument away. I don't know why you would post without even providing the make and model of the instrument.

[JÞB]

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@Dennis_Knutson wrote:
If you don't a manual and don't have any existing software that is communicating to the instrument, throw the instrument away. I don't know why you would post without even providing the make and model of the instrument.

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Yup!

@ DK-  Timing is what Stop and Start bits are there for.  much of the rest comes from reading the friendly manual!  Nothing but love!

[hanumeshbujji]

thanks for reply....thr other end rs 232