LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

VISA TCP/IP wait after query

Hi 

 

I found an issue with the driver to MSO-X 2014A TCP/IP scope which was sending the status request too early after the previous query was issued. 

I have modified the vis, but I was wondering if there is a VISA property node which specifies the wait time after each VISA write is executed?

In that case I could set it upfront and do not worry about the other vis. 

 

thanks

0 Kudos
Message 1 of 5
(3,146 Views)

No.

 

Just use a wait function in series between your write and read.  Many people have created a subVI for that purpose that incorporates the error wire so that you don't have to worry about sequence structures to enforce the wait in dataflow.

0 Kudos
Message 2 of 5
(3,123 Views)
You would not want a general wait after every write anyway. That would just add unnecessary time in the majority of cases. Instead of fixed waits, you can often use the opc? query before doing a read.
0 Kudos
Message 3 of 5
(3,114 Views)

OK, thanks to all. I was just wondering if I can go shortcut, but I guess not. 🙂

 

thanks

0 Kudos
Message 4 of 5
(3,110 Views)

@pawel wrote:

OK, thanks to all. I was just wondering if I can go shortcut, but I guess not. 🙂

 

thanks


The *opc? command IS a shortcut!  Adding it on to the end of a SCPI command turns the previous command into a query.  When the command is done, it sends a "1" (or something similar - I've found different vendors have different interpretations of what a "1" is) to the output buffer that you read so your application only waits exactly as long as it needs to before sending the next command.  You have to look in your programmer's guide to see which of your commands supports this feature.

Bill
CLD
(Mid-Level minion.)
My support system ensures that I don't look totally incompetent.
Proud to say that I've progressed beyond knowing just enough to be dangerous. I now know enough to know that I have no clue about anything at all.
Humble author of the CLAD Nugget.
0 Kudos
Message 5 of 5
(3,088 Views)