The Output Extended Status Instruction, Esc . O - HP 7470A Interfacing And Programming Manual

The following parameters are established:
turnaround delay = 500,
no output trigger character,
no echo terminate character,
output terminator = default value, carriage return,
intercharacter delay = 5,
no immediate response string,
block size = 80,
enquiry character = bell (decimal equivalent 7), and 9
acknowledgment string = ! carriage return (decimal equivalent 33,
13)
Now the computer sends the Bell character as the enquiry character.
The plotter waits approximately 505 milliseconds, the total of the
turnaround delay and the intercharacter delay, before sending its
response. During that time, the computer will send the ? due to the
INPUT statement, but the plotter ignores it. The plotter response to the
enquiry character is now two characters, I followed by a carriage
return. The carriage return to terminate INPUT is now part of the
acknowledgment string. No output terminator, now defaulted to carriage
return, is sent because handshake mode 2 is set here by ESC . I. The
output terminator, carriage return, will still follow all responses to HP­
GL output commands.
The Output Extended Status Instruction,
ESC . 0
DESCRIPTION The output extended status instruction, ESC . O, outputs
the plotter's extended status, giving information about the state of the
buffer, pinch wheels, and VIEW button.
USES The instruction can be used to determine, from a remote
location, if the plotter is ready to plot.
SYNTAX , ()
EXPLANATIONNo parameters are used. Unlike the HP-GL output
status instruction, OS, the ESC . O instruction does not enter the buffer
but is executed immediately, subject to any turnaround or intercharacter
delays specified by ESC . M and ESC . N.
10-38 RS-232—C/CCITTV.24 INTERFACING