167
APPENDIX
Optional parallel interface pins and signal names
Pin
No.
Signal Name Direction Function
1 STROBE IN
Signals when data is ready to be read. Signal goes from HIGH to LOW (for at
least 0.5
µ
s) when data is available.
2 - 9 DATA 1 - 8 IN
Information on the first eight bits of parallel data. Each signal is HIGH for logical 1
and LOW for logical 0.
10 ACK OUT 9
µ
s LOW pulse to acknowledge receipt of data
11 BUSY OUT Printer is ready to receive data when LOW. HIGH indicates one of the following
conditions.
• Data being entered
• Printer off line
• Error condition
12 PAPER OUT OUT Normally LOW, this signal goes HIGH when the printer is out of paper.
13 SELECTED OUT HIGH when the printer is on line
14 — IN This signal is not checked by printer.
15 N/C — Not connected
16 SIGNAL GND — Signal ground
17 CHASSIS GND — Chassis ground (isolated from logic ground)
18 +5VDC — +5V DC (max. 50mA)
19 - 30 GND — Twisted pair return signal ground level
31 RESET IN LOW when printer is reset to power-on defaults
32
ERROR
OUT Normally HIGH, this signal goes LOW to signal that printing is disabled due to an
error condition.
(18) (1)
(36) (19)
