AT&T PC 6300 - Page 352

DIAGNOSTICS
Status bytes may also be displayed to aid in fault isolation. There
are two different interpretations of the bits, depending on the
device that is connected to the port.
LINE STATUS BYTE
Bit?
—
1
Time Out
Bit 6
=
1
Trans Shift Register Empty
Bit 5
=
1
Trans Holding Register Empty
Bit 4
=
1
Break Detect
Bit 3
=
1
Framing Error
Bit 2
=
1 Parity Error
Bit 1
=
1
Overrun Error
Bit 0
—
1
Data Ready
MODEM STATUS BYTE
Bit 7 =
1 Received Line Signal Detect
Bit 6 =
1 Ring Indicator
Bit 5 =
1 Data Set Ready
Bit 4 =
1 Clear to Send
Bit 3 =
1 Delta Receive Line Signal Detect
Bit 2 =
1 Trailing Edge Ring Detector
Bit 1 =
1 Delta Data Set Ready
Bit 0 =
1 Delta Clear to Send
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4-146
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