datasocket Read error 56

[Jochem]

Hello all,
Currently I am working on a project of 350+ VI's used for controlling water filtration installations. The hardware is adressed through the Datasocket VI's (linked to OPC items).
The initialisation of all digital and analog channels (fieldpoint) is executed without any errors. During the first read loop of the analog channels I get error 56 on the datasocket read VI (primitives in 7.1)

"The network operation exceeded the user-specified or system time limit."

I have no idea at all what this error means or how I should solve this situation. What I do now is that when I stop and restart the program no error is seen. When I close Labview completely and start the program again the error will occur again.

It would seem something
is wrong with the initialisation but I isolated the daq part of the program and if this one is ran no error's will occur in any situation.

Does anyone have a clue on what could be the cause of the error in relation to the datasocket VI's (OPC)??

Thanks in advance..

[Eric_BEC]

I am now having a problem similar to the one described here! Is there any solution? I also have to quit the application, and then start it again.

[THailey3]

Hi Eric,

This does indeed seem to be a timeout issue. It makes sense that the first time it times out and subsequent times it doesn't because after connection is established, the connection isn't lost. This will make more sense after reading this thread, especially mhachem's second post.

Getting "error 56 occured at Datasocket Read"
http://forums.ni.com/ni/board/message?board.id=170&message.id=100532&requireLogin=False

Hope this helps,

[Marce]

Hello,

I'd appreciate if you can submit your conclusions regarding the error 56 issue.

Thanks much,

Marce

[THailey3]

Hi Marce,

This seems to be more of an IT/Networking issue. Here is some info from the other thread:

"After further debugging, it turned out that this was indeed a "timeout" issue. Because there was no DNS server, the VI was taking about 25 seconds to find the other machine on the network. This delay only occured the first time the VI tried to read from the remote server. Subsequent calls were much faster even though I was still opening the url everytime (instead of storing a reference and reading from it). Labview must be doing some caching. The way that I fixed the problem was by specifying a timeout of 60 seconds (default is 10 seconds which why it was timing out)."

also:

"Use the IP address in the path instead of the computer name. Then the DNS server will be bypassed."

[stewbert]

hi, i get this error when using the local pc for both reading and writing!