3275 Indicators; System Ready - IBM 3270 Operator's Manual

18
Operating the 3270
3275 Indicators
SYSTEM READY Indicator
SYSTEM READY, SYNC SEARCH, SELECTED, TRANSMIT,
and STATUS are the five indicators found only on display
stations that communicate directly with the computer over
telephone lines.
When SYSTEM READY is on, you know that the telephone lines
are properly conditioned and that your display station is ready
to communicate with the computer.