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vrf Direct I/O vs. MultiInstrument Direct I/O

Question asked by VRFuser on Nov 14, 2001
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"><HTML><HEAD><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2653.12"><TITLE>Direct I/O vs. MultiInstrument Direct I/O</TITLE></HEAD><BODY><P><FONT SIZE=2>Hello VRFers,</FONT></P><P><FONT SIZE=2>Sorry, but this is best seen in a fixed font. If your email reader</FONT><BR><FONT SIZE=2>is not fixed font, just copy and past this into Notepad.</FONT></P><P><FONT SIZE=2>Simple question. If both of these boxes are pointing to the same</FONT><BR><FONT SIZE=2>SCPI instrument that supports this command, (I'm using "PM" for my</FONT><BR><FONT SIZE=2>Agilent E4419B power meter) why does the 2nd box ALWAYS FAIL?</FONT></P><BR><P><FONT SIZE=2>     +------------------+-----------------+</FONT><BR><FONT SIZE=2>     |              Direct I/O            |</FONT><BR><FONT SIZE=2>     +--------------------------------+---+</FONT><BR><FONT SIZE=2>     | WRITE TEXT "SYSTEM:ERROR?" EOL |   |</FONT><BR><FONT SIZE=2>     | READ TEXT x INT16              | x |---> Alphanumeric Display</FONT><BR><FONT SIZE=2>     | READ TEXT y STR                |   |</FONT><BR><FONT SIZE=2>     |                                | y |---> Alphanumeric Display</FONT><BR><FONT SIZE=2>     +------------------+-------------+---+</FONT><BR><FONT SIZE=2>                        |</FONT><BR><FONT SIZE=2>                        |</FONT><BR><FONT SIZE=2>   +--------------------+--------------------+</FONT><BR><FONT SIZE=2>   |       MultiInstrument Direct I/O        |</FONT><BR><FONT SIZE=2>   +-------------------------------------+---+   </FONT><BR><FONT SIZE=2>   | WRITE "PM" TEXT "SYSTEM:ERROR?" EOL |   |</FONT><BR><FONT SIZE=2>   | READ "PM" TEXT x INT16              | x |---> Alphanumeric Display</FONT><BR><FONT SIZE=2>   | READ "PM" TEXT y STR                |   |</FONT><BR><FONT SIZE=2>   |                                     | y |---> Alphanumeric Display</FONT><BR><FONT SIZE=2>   +--------------------+----------------+---+</FONT></P><BR><P><FONT SIZE=2>The string coming back from the instrument is: +0,"No error" (assuming</FONT><BR><FONT SIZE=2>you have no errors in the buffer). The Direct I/O box gives zero for the</FONT><BR><FONT SIZE=2>"y" output pin and the "x" pin has the text: No error. Exactly what I</FONT><BR><FONT SIZE=2>would expect.</FONT></P><P><FONT SIZE=2>The MultiInstrument Direct I/O box times out with a read error on the</FONT><BR><FONT SIZE=2>3rd line. Can someone tell me WHY?</FONT></P><P><FONT SIZE=2>Mike Groves</FONT><BR><FONT SIZE=2>UltraRF a CREE Company</FONT><BR><FONT SIZE=2>mike.groves@ultrarf.com</FONT></P></BODY></HTML>  

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