ExtendedMainframe3270 is a fork from original Altran's library used for Robot Framework
I've added session file handling so You can use *.wc3270 session file and specify all needed parameters inside.
wc3270 Resource can be found on official x3270 site
*** Settings ***
Library ExtendedMainframe3270
*** Test Cases ***
Example
Open Connection host=resources\\pub400.wc3270 isSessionFile=${True}
Change Wait Time 0.4
Change Wait Time After Write 0.4
Set Screenshot Folder C:\\Temp\\IMG
${value} Read 3 10 17
Page Should Contain String ENTER APPLICATION
Wait Field Detected
Write Bare applicationname
Send Enter
Take Screenshot
Close Connection