Hello,
I've created a TCP/IP with XML server and client to be used as our standard connection between any remote systems and the main running application using the vi's described at http://zone.ni.com/devzone/conceptd.nsf/we...6256F170079411E. I've tested it out using localhost on a single computer as well as on two separate PC's running Windows on our intranet and everything works great. But when I send the target vi to a remote PXI chassis and run the host vi on a laptop connected only to the remote system (I've used a crossover cable linking the two directly and a patch cable with a hub in between, but either way the only two pc's on the system are the remote PXI and the laptop) I'm getting a failure.
I'm using a PXI 1045 chassis with an embedded 8187 processor running LV7.1 RT only - no Win OS on the remote system. The laptop is running Win XP with LV 7.1. At this point I'm not making any attempt to utilize anything on the PXI chassis other than the TCP communications.
The problem I'm seeing is the Read Meta.vi (located in the host vi running on the laptop) is only getting 4096 bytes, then the I get error 66, connection closed by peer (the remote PXI running the target vi - Write Meta.vi). The bytes to read value within the Read Meta.vi is 5450, which is the correct number of bytes needing to be read, but then it only reads 4092 bytes (4096bytes minus the 4bytes telling how many bytes to read) and so the XML data gets corrupted and the resulting error stops the vi's before they really get started.
1. Why would this do that?
2. Does anyone know anything about a packet size limit for PXI - TCP? I understand that LV 7.1.1 has a fix to allow packets to be up to 65536 bytes, which would solve my problem I believe, but we will want this to be used by hosts and remotes that run with LV 7.1 (and possibly earlier versions), so I need to resolve this 4096 byte issue as it is.
3. Do I need to rewrite the Read Meta & Write Meta code so that it breaks the data packets into maximum sizes? I was under the impression that TCP/IP communication did this automatically, is that incorrect?
I just downloaded the Maximum TCP Transfer vi's and will play with those, maybe I'll find something there.
Thanks for any help,
Scott