Effects of Entering a Null Line

When you are communicating with TSO/E and Session Manager, you may want to send a null line to TSO/E. To enter a null line, position the cursor at the beginning of a field on the screen, press ERASE EOF, and then Enter.

If you press the Enter key without pressing ERASE EOF or without modifying a field, a null line will not be sent to TSO/E. Instead, Session Manager interprets this action as a request to automatically scroll unlocked windows over lines of output that were generated by your TSO/E application since the keyboard was last unlocked.

Sending a changed field to TSO/E and sending a null line can produce the same result from Session Manager. For example, a full-screen application, such as ISPF, may suspend its operation to permit line-mode output to be written to Session Manager data streams. You may then see this message:

ADF041A ENTER A NULL LINE TO RETURN TO FULL-SCREEN PROGRAM

Message ADF041A may be displayed before you have had an adequate opportunity to read the line-mode output. You can scroll through the line-mode output by sending scroll commands to Session Manager or by using the program function keys that allow you to scroll.

When you want to reactivate the full-screen program, you can enter a null line. However, if you change a field intended for TSO/E (for example, if you enter a TSO/E command) and press the Enter key, the data is not sent to TSO/E, but rather it is interpreted by Session Manager as a request to reactivate the full-screen program. In this case, Session Manager interprets the changed field as a null line.