It just took me a few hours to get this working so here are some tips for others… most of it can be found in other comments here but this is what I learned: a) the serial port is identical to a pc – this means you need a null modem connection. Make your own like this: (These are the DB9 RS232 connectors on the wiznet board and on the pc) pin 5 to pin 5 GND pin 3 to pin 2 pin 2 to pin3
b) I think most boards probably come with a default IP address of 192.168.11.2 so if this matches the network you are trying to use, great. Most of us probably have something else like 192.168.1.xxx or 192.168.10.xxx, etc. You must change your board IP address using the Wiznet config tool to match your network.
On both windows 7 and win-xp, the config tool quickly connects to the board even with a screwy IP address. This leads you to think your pc can now communicate to it. Then when you try to do so, nothing happens. My network is 192.168.10.xxx so I used the config tool to set IP addresses as follows (based on our IT guys advice for the last octet trying not to collide with other equipment already in place): Local IP 192.168.10.85 Gateway 192.168.10.1 Server IP 192.168.10.86 and bingo – comms working both ways now.
If any IT gurus out there see mistakes or think this needs further clarification, please add your 2 cents. Hopefully this will get future people up and running.