The Output Buffer Space Instruction, Esc.b - HP 7470A Interfacing And Programming Manual

Bit Logic
No. State Description
0 0 Set and hold line high (disable hard­
wire handshake).
1 Enable hardwire handshake mode.*
1 X Ignored.
2 0 Establish monitor mode 0 (all bytes
displayed on terminal as they are
parsed from the buffer).
1 Establish monitor mode 1 (all bytes
displayed as they are received).
Disable monitor mode. H
1 Enable the monitor mode established
by bit 2.
*When hardwire handshake is enabled, the DTR line becomes
a "buffer space available" flag. The line is high when available
buffer space is greater than or equal to the current block size,
and is held low when available buffer space is less than the
current block size. This size defaults to 80 bytes unless a
different value is specified by the ESC . H or ESC . I command.
EXAMPLE . @;13: will establish monitor mode 1 where all bytes
are displayed on the terminal as they are received by the plotter.
The Output Buffer Space Instruction,
ESC.B
DESCRIPHUN The output buffer space instruction, ESC . B, outputs
the plotter's available buffer space.
IIEE This command is used in a software checking handshake to
interrogate the plotter regarding available buffer space.
SYNTAX , B
EXPLANATION No parameters are used.
<DEC>
[TERM]
The plotter's response is a decimal number in the range
0 to 255, and represents the number of bytes of buffer
space currently available for storing graphic instructions
sent from the computer.
This decimal number is followed by the output termina­
tor which defaults to carriage return, CR, or is as set by
ESC . M.
10-26 RS-232—C/CCITTV.24 INTERFACING