Epson Stylus Pro 7500 - Page 25

EPSON Stylus Pro 7500 Revision A
Product Description Interfaces 25
*1 The return side means the twisted pair return and is connected to the signal ground level.
Furthermore, when interfacing, a twisted pair cable should definitely be used for each signal
and the return side should definitely connected. Also, use of a shielded cable and
connection to the chassis ground of the center machine and the printer, respectively are
effective countermeasures against noise.
*2 All the interface conditions are TTL level standard conditions. The rise and fall time of
each signal is 0.2 _s or less.
*3 For details on the timing of each signal, see the “Data Transmission Timing” diagram in
the figure below.
*4 There must not be any data transfer with disregard of the /ACKNLG or BUSY signals.
(Data transfer to this printer must be performed when/ACKNLG is confirmed or when
BUSY is in the “LOW” state.)
*5 If appropriate character codes are set for DATA 1~8 of the interface connector (as
opposed to “1” for GND open and “0” for short circuit), and BUSY and /STROBE are
connected, an external device is not used and a printing test can be performed, which
includes the interface circuits.
*6 The printer is in the following states when the PE signal line enters the Assert state (“L”
Level).
• Out of paper error occurring (ST:00 ER:06 state)
• Other paper errors occurring (ST:00 ER:0E, 12, 13, 14, 15, 16 state)
o Data Transmission Timing
Figure 1-5. Data Transmission Timing
Table 1-15. Timing Chart Parameter
Parameter Minimum Maximum
tsetup 500 ns -
thold 500 ns -
tstb 500 ns -
tready 0 -
tbusy - 500 ns
tt-out* - 120 ns
tt-in** - 200 ns
treply 0 -
tack Typical 2 us
tnbusy 0 -
tnext 0 -
DATA
-
STRO BE
BUSY
-ACKNLG
data byte n
data byte n+1
thold
tsetup
ts tb
tnext
tready
tbusy
tre p ly ta c k
tnbusy