HP 7470A Interfacing And Programming Manual page 181

RESPONSE
<DEC> The response is the decimal equivalent of a 16-bitimme­
diate status word, followed by the output terminator.
The maximum value output is 40.
The extended status word bits are as defined in the
following table.
Decimal
Bit State Value Meaning
0-2 0 0 Not used, always zeros. Re­
served for plotters with
paper advance.
3 0 0 Buffer is not empty.
1 8 Buffer is empty and ready
for data.
4, 5 00 0 Ready to process or process­
ing HP-GL instructions.
01 16 Paper loaded, VIEWbutton
pressed so graphics sus­
pended.
10 32 Paper lever raised so graph­
ics suspended.
Combinations of these bits allow five different responses
to the ESC . O instruction.
Response Meaning
0 Buffer is not empty and plotter is process­
ing HP-GL instructions.
8 Buffer is empty and is ready to process
or is processing HP-GL instructions.
16 Buffer is not empty and VIEW has been
pressed.
24 Buffer is empty and VIEWhas been
pressed.
32 Buffer is not empty and paper lever and
pinch wheels are raised.
40 Buffer is empty and paper lever and
pinch wheels are raised.
[TERM] The output terminator defaults to carriage return unless
it is set by ESC . M.
RS-232-C/CCITT V.24INTERFACING 10-39