Datasocket diagnostics

[pkripak]

I am having difficulty figuring out the meaning of the information in the datasocket server diagnostics tool. It shows the number of packets received, packets sent and packets dropped. When I only run the VI that publishes the data, there are no packets dropped but the number of packets sent and number of packets received are the same. I am unable to understand why the server has to send out packets when there is no client subscribing to the data.

If I then run a remote client that subscribes to the data, then there are a lot of packets dropped. In fact, it seems like there is a dropped packet for every packet received. The number of packets sent still equals the number of packets received. Can anyone shed some light on this?

Thanks,
Prakash K

[AESulzer]

Prakash,

When data is published to the DataSocket Server, two events occur: (1) a packet is received from the publisher, and (2) an acknowledge packet is sent back to the publisher. This acknowledge packet explains why you see the same number packets sent as you see received while running a publisher by itself. When you run a reader on the same PC, it does not increase the number of packets sent because it is using the same client as the publisher. If you were to run a reader on another PC, you would notice that the number of packets sent would double (one acknowledge packet to the publisher, and one to the reader).

As for the packets dropped, this is not normal and is indicative of another problem. Running the DS Reader/Writer examples that ship with LabVIEW, you should notice that no packets are dropped. It is a good idea to try to model your own DataSocket VIs after those or other shipping examples. There is a good Knowledge Base on trouble with dropped packets, and I've linked it here.

Regards,

Message Edited by AESulzer on 04-29-2005 03:40 PM

[pkripak]

Sulzer,

Thanks a lot. That example was very helpful in fixing the problem.

Prakash K