Cyclic data exchange between cRIO and S7

[MichaDu]

Hi,

I want to exchange data between a CompactRIO (stand-alone) and a PLC (S7-300 with CP343-1) via native TCP/IP sockets

- control data: S7-Send -> cRIO-Receive

- measurement data: cRIO-Send -> S7-Receive

The send and receive is independent to each other and should be asynchronous.

I don't (want to) use OPC. May be, it is also not possible due to VxWorks-OS.

Now I have some questions concerning the programming

1. Can I use only one socket for send/receive (either client or server)?

If yes, should I exchange data sequently in one loop (client: send-receive or server: receive-send) or "parallel" in two loops (send and receive separately)?

2. Is it better (or even necessary) to use two separate connections for my purpose (client-send and server-receive)?

I'm not very familiar with S7, but I heard it is easy to project either one or two connections.

Thanks in advance!

Edited August 7, 2009 by MichaDu