Interface Specifications; Parallel Interface - Epson SQ-2550 User Manual

Interface Specifications

Parallel
interface
Your printer is equipped with both a parallel and a serial
interface.
Connector pin assignments and a description of their respective
interface signals are shown in the following table.
Signal Return
Pin Pin
1
19
2
20
3
21
4
22
5
23
6
24
7
25
8
26
9
27
10
28
11
29
12 30
13
8-10 Technical Specifications
Signal Direction
IN
STROBE
DATA 1 IN
IN
DATA 2
IN
DATA 3
IN
DATA 4
IN
DATA 5
IN
DATA 6
IN
DATA 7
IN
DATA 8
OUT
ACKNLG
OUT
BUSY
PE OUT
SLCT OUT
Description
STROBE pulse to read data. Pulse
width must be more than 0.5
microseconds at the receiving
terminal.
These signals represent information
of the 1st to 8th bits of parallel data,
respectively. Each signal is at HIGH
level when data is logical 1 and LOW
when it is logical 0.
About a 12-microsecond pulse. LOW
indicates that data has been received
and that the printer is ready to accept
more data.
A HIGH signal indicates that the
printer cannot receive data. The
signal goes HIGH in the following
cases:
1) During data entry (ea. char. time)
2) During printing
3) When off line
4) During printer-error state
A HIGH signal indicates that the
printer is out of paper.
Pulled up to +5 volts through 3.3K
ohm resistance.