Experimental Physics and
Industrial Control System

Mark Rivers via Tech-talk <tech-talk at aps.anl.gov> · Mon, 20 Jul 2020 22:58:12 +0000

This is a good time to load an asynRecord into your IOC and open the OPI display for it.  You can then interactively send commands and look at the response, changes the EOS terminators, and turn the debugging on and off.

https://epics-modules.github.io/master/asyn/R4-40/asynRecord.html

Mark

________________________________
From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Hu, Yong via Tech-talk <tech-talk at aps.anl.gov>
Sent: Monday, July 20, 2020 5:41 PM
To: Daniel Cuneo; Eric Norum via Tech-talk
Subject: Re: TCP to LabVIEW TCP VI using Stream Device.

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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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System