labview TCP to replace telnet

[rolfk]

Telnet is a specific protocol that you need to implement on top of TCP/IP. If you changed your telnet server (your target) then that telnet server probably does some default option negotiation in the beginning and expects an according answer that Putty of course implements. In LabVIEW you have to do it yourself explicitly.

The images you provide of the VIs are NOT implementing any telnet protocol. They are just simple wrappers around the TCP Open, TCP Read and TCP Write and as such also not implemented in a very usefull way.

So either your old target was not really implementing telnet but just a very simple direct remote shell interface, or you have not shown the real VIs that are implementing the telnet part.