Instrument Control (GPIB, Serial, VISA, IVI)

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Why can I only read 8 bytes of data on a VISA serial read the first time around?

I am trying to read data from a data logger. After I send a command to the logger, I am expecting to get back 64 bytes of data. The VISA read VI sees all 64 bytes, but only reads 8 of them. It returns a count of 64. If I read it after that, it will read all 58 other bytes. How do I get it to read all 64 bytes on the first time around?
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Hi,

I did a loopback test with your VI and didn't get the same results. Basically, I connected the Rx and Tx pins of the COM port together. I send a string of 64 character and the VI read the whole 64 characters in one read.

I'm attaching a screen shot of the front panel of your VI with the data I sent.

Check how your instrument is sending the data. You can use hyperterminal to see what it is returning.

Diego Funes.
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