RS232 interface

[kingmoro]

im doing this interface for an rs232 stream containing a value in hexadecimal at a resolution of 5hz, rs232is  9600 baud rate, no parity, 8data bits, one stop bit, crc, handshaking

convert it into decimals, gather 256 values (which will take 50 seconds)  then process this array for my needs...

the problem is while im processing the data wont be other values coming in at the rs232 terminal !!!!!!!! WAHAT SHALL I DO 😞

S>O>S

thnx

[J.Harv]

King--

      So when you send your instrument the command to start generating data, you will then tell the VISA read vi how many bytes of data to acquire and this will be how you will get the information that you need.  It will all come in as one text array and then you will have to parse through it and separate it yourself.  Often it will be separated by commas or some other delimeter.  After that if the instrument is still sending data you could get a hardware buffer overflow.  The easiest way to fix this is to simply send the instrument the command to stop.  However, in your post you said that you are using handshaking (Xon/Xoff) this should automatically tell the instrument to stop when the buffer limit has been reached.  If not then you could periodically send a command to flush the buffer using VISA flush I/O buffer vi.

    Most of your questions could be anwered by going to the serial support page at http://www.ni.com/support/serlsupp.htm and if you can't find enough information there then you can simply search our site with what you want to know. There is a ton of infomation on our site.  I would suggest that you actually try it out.  That is the best way to know what kind of problem that you will run into.  Furthermore, when you do that if something does happen to go wrong then you will have an error message to go by and you can look that up at our site and find specific information regarding how to fix the issue.  If you still have a problem after you have searched or can't figure something out then let us know and we'd be happy to help.

Regards,

John H

Applications Engineer

National Instruments

http://www.ni.com/support