RS232 DB25 pins read

[lavalava]

Does Labview supports read/write to DB25 pins syncrhonous serial card because all the examples that I have seen were designed for DB9 only?  Does anyone have an example of how to get this working in VISA mode?  Also, how do I program it so that it waits until it found my sync sequence? 

Thanks

[Albert.Geven]

From software point of view there is no difference between Db9 or Db25 serial. The only difference is the cabling and the connector.

Realise that the send and receive are swapped between the 2 connectoors

[lavalava]

how do I get it to listen until it found a sync pattern then start pulling in data?

[Albert.Geven]

If it is rs232 it should do it automatically and all you need to do is to set the correct baudrate, number of bits per character, stopbits handshakke and some other details and you will receive characterbytes in a string.

[lavalava]

is there a way to set to automatically detect external baud rate in synchronous mode?

[Albert.Geven]

No

This is a protocol defined somewhere in 1965 !!

[lavalava]

It should be for DB25, the clocking features is what set DB25 apart from DB9.  All those extra pins were mostly gearing toward the clock and balance.  Here is an example of one of the analyzer we bought that I'm trying to emulate in Labview.  If you look at this setup that we normally used, it allows to capture data using external clock, i.e. NRZ, and automatically detects the external baud rate using the configuration shown in this picture.

 

Message Edited by lavalava on 02-24-2009 01:31 PM

[Albert.Geven]

This is not normal rs232, so nothing to do with db9 or db25 but a special probably IBM related protocol.

The ebst you can do is use an NI FPGA card and build the recognition and tranlation with LabVIEW in that Fpga.

At the moment they can go up to almost a GHz

[lavalava]

NI doesn't sale DB25 RS232 cards, only DB9 were available.  And this is a normal classic DB25 RS232.  There is really nothing special about it as far as I've known it.  Just about any commerical off the shelf analyzers we purchase works fine with no modifiication required.

[Albert.Geven]

Hi

You are right, and indeed this is an IBM protocol.

maybe you can use this link to get the stuff into a pc directly

http://www.fte.com/products/Serialtest-01.asp?RKG=625939

And maybe you can control this card from LabVIEW.