Re: TCP to LabVIEW TCP VI using Stream Device.

["Hu, Yong via Tech-talk" <tech-talk at aps.anl.gov>]

Hi Daniel,

 

Add these two lines in your startup script or type them in the EPICS shell:

asynSetTraceMask("your-asyn-port",-1,0xff)

asynSetTraceIOMask("your-asyn-port ",-1,0xff)

 

And you will see what is really going on. Post more debugging messages so that other people probably can help you figure out the issue.

 

Good luck!

Yong

 

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Reply-To: Daniel Cuneo <dpcuneo at lbl.gov>
Date: Monday, July 20, 2020 at 6:08 PM
To: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Subject: TCP to LabVIEW TCP VI using Stream Device.

 

Hello all,

 

My co-worker has setup a TCP virtual interface in LabVIEW, that allows me to send commands

as strings of text, and get replies with data.

 

Testing in a Linux shell using netcat (nc on CentOS 7) works well.

 

echo "foobar\r" | nc -h hex.dump labview-host.foo.bar

 

However, when I attempt to use Stream / Asyn, I get only timeouts.

Stream and asynOctetWriteRead()  both timeout.

 

One would usually suspect that the line terminators are incorrect. To test line terminators, I turned on the netcat hexdump and can see both a CR and LF (0xD 0xA) being sent in a working netcat test. I put both in my stream protocol file and hard coded when using asynOctetWriteRead.

 

I'm beginning to wonder if there's a protocol difference between what netcat does and what a generic TCP connection does. 

 

Does anyone have advice on what else I can try to tease out the problem ?

Cheers and TIA !

dpc

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Daniel Cuneo

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