IBM 3270 Emulation
Network Virtual Terminal Mode
Network Virtual Terminal (NVT) mode allows the operator to communicate with a network gateway (in ASCII) for routing, logon etc, before the full IBM terminal
emulation protocol is established. NVT mode is indicated by the ?
symbol in the status line along the bottom of the display.
NVT mode displays an unformatted screen for data entry, allowing most of the keyboard functionality for local editing. However, when the Enter key is pressed, the line that the cursor is positioned on will be sent over Telnet as an ASCII string with CR/LF terminators. The cursor will then be positioned at the start of the next line. ASCII data received over Telnet will also be displayed at the current cursor position. A CR character will be actioned as a 'new line' character, causing the cursor to move to the start of the next line, scrolling the display if necessary. Once the appropriate details have been entered to establish an IBM host session (which may be automatic), the screen is cleared and switched into full IBM 3270 terminal emulation mode, as indicated by the 
symbol in the status line.
TN3287 printing is supported by setting the IBM 3270 Model option in the IBM 3270 Settings dialog box to
When printing commences a Print Abort box will be displayed enabling you to cancel the print job. Note that this will stop print data being sent but will not disconnect you from the host.
SysReq Key SupportWhen the SysReq option in the Telnet Options dialog box is selected, the key mapped with the SysReq function enables you to toggle the display and keyboard entries between the host operating system and the application. This enables you to switch to the operating system and issue a LOGOFF command. When communicating with the operating system the status line will display the 
symbol.
Note: Not all TN3270E servers provide full support of the SysReq key.