Visa Read Timeout on High Resolution Mode

[matt_gf]

I'm trying to control an Advantest Q8347 Spectrum Analyzer with a LabView program. One of the objectives of the program is to export the X and Y axis data to a .txt file. When I'm in the normal resolution mode, it runs perfectly, I can save the data in the file and it does what I want. The problem is, when I change to the High Resolution mode and try to export the data I get the Timeout Error -1073807339 in the Visa Read. I've already increased the timeout in the device, and also put a delay between the Visa Write and the Visa Read block, and I still have the same problem. The communication works, if I try to send and read the same command directly to the instrument using the Interactive IO it works no matter the resolution. Any idea on how I can fix the Timeout Error in the High Resolution Mode?

[crossrulz]

When in the interactive mode, how long does it take to get the data when in the high resolution mode?  What do you have as the timeout?

[matt_gf]

In the interactive mode it takes around 5000ms to get the data and the timeout is set in 7000ms

[crossrulz]

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@matt_gf wrote:

In the interactive mode it takes around 5000ms to get the data

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Just to be clear, is that the get all of the data or just for the data to start coming in?

[billko]

I'm guessing this instrument uses SCPI to interface with the instrument.  Usually (but not always), you can turn a SCPI command into a query by adding ;*OPC? to the end of the command (followed by a VISA read).  The instrument will then process the command - in this case, it will finish gathering data - and place a "1" (or something similar) in the read buffer for the VISA read to read.  Then do whatever it is you do to get the data.  Check your programmer's guide to see exactly how to implement this, or if it's even possible.

[Ben]

Are you increasing the timeout of the VISA connection?

You may not be waiting long enough to the device to send all of the data.

NI IO Trace will show you is happening and may give you some insight.

Ben

[gabriellnuness]

Hello, I'm working with the same instrument and unfortunately it does not communicate with SCPI standard, neither IEEE 488.2. This spectrum analyzer works with 488.1. I am trying to figure out a way to read the status byte to get the service request from the device to know when the measurement is finished, but I don't know how to do it with LabVIEW. There is a command "SRQ" in the user's manual that enables the SRQ signal transmission, however the "SRQ?" command only returns the state I previously set. So I want to get the status byte using general 488.1 communication to check if the Service Request signal is working. Do you know how can I achieve this?

[gabriellnuness]

I just figured out a way to make it work. Somehow the LabVIEW VISA function "read status byte" works even though "STB?" does not. With this signal I managed to implement a while loop to wait the signal go to 1.

[JÞB]

Put the splat, "*", in "*STB?"

[RTSLVU]

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@JÞB wrote:

Put the splat, "*", in "*STB?"

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I know it's off topic but back in the 90's my company used an ancient UNIX based MRP system and in it the Exclamation Point "!" was called a "splat", the Asterisk "*" was called a "star".