IBM 3180 1 User Manual page 59

- S The symbol you typed is not recognized by the control unit.
Press the Reset key.
X A message from the control operator was received and rejected.
Press the Reset key.
X - f You tried to change the PS or highlighting selection when the
program will not allow it. The keyboard is locked as a result.
Press the Reset key.
X —z- You pressed an X.21 function key under the wrong conditions.
X N2 Your keyboard ID does not match the keyboard ID assigned to your
I display station by your control unit.
I
I Press the Reset key or retry the operation.
Chapter 3. Operator Messages and Error Codes 51