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<== Date ==> <== Thread ==>
Subject: TCP to LabVIEW TCP VI using Stream Device.
From: Daniel Cuneo via Tech-talk <tech-talk at aps.anl.gov>
To: Eric Norum via Tech-talk <tech-talk at aps.anl.gov>
Date: Mon, 20 Jul 2020 15:06:43 -0700

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
--
Daniel Cuneo
ALS Accelerator Controls
BLD 46-172G
desk: 510-486-5439
cell:   415-871-1909
Replies:
Re: TCP to LabVIEW TCP VI using Stream Device. Hu, Yong via Tech-talk
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