I had the same problem and this topic saved my life ahaha..
I have a NT11 V1 with a broken display and I couldn't find a replacement so I bought a second-hand NT11S.
1- After having problems with the communication I did my own cable like Michael Walsh told above and all communication worked ok.
2- Downloaded application from NT11 V1 and uploaded on NT11S. After opening the application from NT11V1 you should go to TOOLS > PT CONFIGURATION > and change PT MODEL to NT11S. After, upload the application.
3- When connecting to PLC go to maintenance mode and change the baud to 19200. DONE!!!!!
That was my experience, I hope it helps someone in the future...