200 ms UDP Read timeout causes error ( but works in UDP Receiver.vi)

[jlivermore]

A 200ms timeout works in the UDP Read in the UDP Receiver.vi, but doesn't seem to work in general (get error 56 - network operation exceeded user-specified or system time limit). Any idea why a 200ms timeout doesn't work in general (when I construct my own UDP receiver vi)? I have examined the properties of the numeric constant which specifies the timeout. It appears to be the same as the numeric constant in the UDP Receiver.vi, but apparently there is some subtle difference. TIA.

[MikeS81]

Hi jlivermore,
can you attach your code or a picture of it? Maybe 200ms are not enough in your vi?

Hope it helps.
Mike

[smercurio_fc]

Is your UDP sender running on the same computer, or on another computer? It quite unlikely that the properties of the numeric constant are your issue. The only properties that matter are the value and the datatype, and with the datatype, a coercion will occur if your constant is, say, a U32, since the UDP Read expects and I32. The only time the datatype would matter is if you are going into a datatype that's of a smaller numeric range than the value that you have (for example trying to stuff the value 300 into a U8, since a U8's maximum value is 255).

[jlivermore]

Mike-

The 200ms works in the NI UDP Receiver VI, but not when I use it in my UDPR.vi which is based on the NI VI. I can use the default value of 25000ms, but I'm curious why 200ms works in the canned VI, but not in mine. Thanks.

-Jesse

[jlivermore]

Mercurio-

I'm using different computers for send and receive. I can use the default timeout value of 25000ms. That's works. I just curious why 200ms works in the canned NI UDP receive VI, but not in mine. Thanks.

-Jesse

[smercurio_fc]

Please post your code. We cannot magically see what you are doing via telepathy.

[jlivermore]

Mercurio-

Here is the code. It works with a timeout of 25000ms, but not with a timeout of 200ms. Thanks.

-jesse

[smercurio_fc]

Your problem is that you have the "no timeout error" on the block diagram not connected to anything. The way the example VI is designed to run is that it only sits in the UDP Read function for a short amount of time. If there are no bytes you get a timeout error. The "no timeout error" VI negates that error. However, it can only do so if you actually connect it into the error cluster stream.

[jlivermore]

Merc-

You asked if the UDP send/receive are running on the same computer? How can I do that..run them on the same computer? That would save check-out time. TIA.

-jesse

[jlivermore]

THANK YOU, MERC.

I was going by the block diagram display which appeared to show the "no timeout" icon attached to another wire. Problem fixed.

-jesse