LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Error 56 Occurs When Using TCP Read.vi

TCP Read gives Error 56: The network operation exceeded the user-specified or system time limit?

TCP Read in my application in not reliable. It works sometime, but it fails some other time. I tried to read just 1 byte, and set time out to be 1 min, I still get error code 56. What could cause this problem?
0 Kudos
Message 1 of 3
(3,620 Views)
Most of the time it is due to a poor implementation of TCP-IP and the protocol implementation ontop of that.

There can be several causes.

Once the device we talked to could not handle the network traffic, resulting in several TCP-IP retries (part of TCP-IP) and showing the result only after minutes. There was loads of traffic on the network and the device was overloaded with traffic it shouldn't even been listing to. Solution was a router.
It could just as easily be something else.

Please post a screenshot or code snippet that shows your implementation and we can give you pointers.

André
Regards,
André (CLA, CLED)
0 Kudos
Message 2 of 3
(3,608 Views)
How good is the TCP connection between the two computers? Do some line testing. Could be a bad adapter, bad cable, duplex mismatch, corrupt NIC driver, etc.
 
You might also want to sniff some of the traffic (e.g. using ethereal (http://www.ethereal.com/)).
0 Kudos
Message 3 of 3
(3,606 Views)