My company is implementing FTP on the W5200, but we are having a problem in that everything works well with just socket 0 open on the command port, but when we open socket 1 for use as the data channel, we run into the problems noted below.
For example, when we issue the USER and PASS commands to get logged in, then issue a QUIT all is well; we get the proper responses from the server.
The problem becomes when we open the data port. We don’t any longer get all the proper messages back via the command port. Worse yet, we are getting a 425 error code from the server, which means it is not happy with the port we are trying to send the data to, even though we are using the port that the server passed to us as a result of us having sent the PASV command.
We have spent many man-hours trying to resolve this problem. It becomes even more burdensome in that we have over 80 of the W820io modules in the field that require an important upgrade once this problem is solved.Once this problem has been resolved, our customer plans on purchasing 500 more modules.
Your early attention to this would be greatly appreciated. If you need more information or if we can answer any questions, please do not hesitate to let us know.
CNC International LLC
Loveland Colorado USA