Panasonic KX-T336 System Reference Manual page 519

A. Introduction
This section describes the information necessary
for monitoring, testing, and maintaining the
system using VT220 (VT1 00) or Compatibles in
interactive format.
The modular self-testing capabilities of the
system allow most maintenance to be reduced to
simple procedures.
You can administer the system programming and
maintenance of the system using a Vr220
(VT1 00), Compatibles, Dumb terminals or an
Attendant Console.
Only one terminal can be performing system
administration at any one time.
Changing the System Administration Device is
done by programming.
To execute the change, you must exit system
administration mode and then reenter system
administration mode.
14-A-l