HP 7470A Interfacing And Programming Manual page 112

The Output Status Instruction, OS
DESCRIPTION The output status instruction, OS, is used to output the
decimal equivalent of the status byte.
W This instruction is useful in debugging operations and in
digitizing applications.
SYNTAX OS (terminator)
EXPI-ANA]-'0" No parameters are used. The instruction will execute
even if no terminator is received.
Up- eipt of the OS instruction, the internal eight-bit status byte is
"*1 Ledto an integer between 0 and 255. Output is in ASCII in the
Iorm:
status [TERM)
The status bits are defined as follows:
Bit Bit
Value Position Meaning
1 0 Pen down.
2 1 P1 or P2 changed; cleared by reading
output of OP in HP—IBor HP—ILsystem
or by actual output of P1,P2 in RS-232-C
system.
4 2 Digitized point available; cleared by
reading digitized value in HP-IB or
HP-IL system or by output of point in
RS-232—Csystem.
8 3 Initialized; cleared by reading OS output
in HP—IBor HP—ILsystem or by output
of the status byte in RS-232—C system.
16 Ready for data; pinch wheels down.
32 5 Error; cleared by reading OE output in
HP-IB or HP—IL system or by output of
the error in RS-232—C system.
64 6 Require service message set (always 0
for OS ;0 or 1 for HP-IB serial poll).
128 7 Not used
Upon power up, the status is decimal 24, the sum of 8 (initialized) and
16 (ready for data). Upon output of the status byte after an OS
command, bit position 3 is cleared.
7-8 OBTAINING INFORMATION FROM THE PLOTTER