Table 5.1 Centronics-compatible interface signal lines
Signal
level
Signal name
(+)
Direction
COIlCentS
1O
System---Printer
Data Bit 1
to
5
V
0
I
These signals are data (character code, FCB data,
Data Bit
8
control code) input from the lost
co
the printer.
(DBL-DBB) DBS
is used when the
12,5-character-set
print band
is used. (For ASCII
'i-bit codes,
DBS
can be
ignored.)
Data Strobe
0
su
-
This signal is a synchronizing clock for reading
DBI-DBB input to the printer. The data is read
at the rising edge of this signal.
[nput
Prime
0
SV
This signal initializes the printer. Wnen it
receives this signal, the printer clears the FCB,
PDB, and control functions and goes offline.
After clear, TOF is the first line and BOF is the
last
line. When this signal is received during
printing or forms feed, the settings are cleared
after the operation.
hlsy
5V
0
When this signal is
1,
the printer is not ready
to
receive data.
This signal is issued
in
one of the following
cases:
. During printing
. During forms feed
. During offline state (including the TEST and
SE'I
UP
modes)
. When the printer is inoperable (fault state)
When the printer responds to a control code
(except the DC1 code)
. When the printer responds to each VFU data byte
following to the start: code
(X'3.D')
Acknowledge
I0
5v
This signal is sent to the mainframe when the
printer can receive data. This signal is used to
inhibit sending signal by the host until the
printer operation such as loading the received
code. This signal is sent with a 2.5 to 5.5 us
width pulse.
Fault
0
5V
'!&is
signal
is issued during an error
state
or
another or inoperable
st:ate,
such as top cover
open or end of
farms.
(Fault state)
B02P-1500-OOOlA...O5
5
-3