Problem:

While loading screen using either EL Loader or loader lite ther is noway to specify which protocol

to use TN3270 or TN3270E  but there is a option after the project is created.

Resolution:

At the start of loader in the information page under the category "Display Attributes" there is a checkbox  "Extended mode".   

TN3270E is extended mode.   

And is this also true for LoaderLite, the "Extended Attributes" check box turns on TN3270E?