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REV.-A
Circuit Description
Figure 2-48 shows the
serial interface circuit. Data transmitted from the host computer is
converted from
(+3 to +27 V, –3 to –27 V) to
O V, + 5 V voltage levels by the
line
driver 75189 (3A). The converted data is sent to the main CPU via buffers in the
(1 1 B). On
the contrary, data transmitted from the main CPU is sent to the 75188 (4A), converted from TTL to
voltage levels, and transmitted to the host computer.
The sequence for the serial interface operation is shown in Figure 2-49, and that for handshaking in
Figure 2-50.
+ 1 2
- 1 2
D1
D2
of
4A)
7 5 1 8 8 ( 4 A )
CN3
1
4
36 6
4 ‘
-
“
6
5
EBUSY
MAIN-CPU
L - - - - -
- - - J
( 1 3A)
1
& 2
3
2
1
1
1
- 1 2
1
1
1
R22
I
1
1
1
1
7 5 1 8 9 ( 3 A )
9
10P (1 1
B)
,- - - - -
-
1
RxD
10
1
B02
– – – – – – – – - - .1
14
—
FG
7
I
4 13
777
Figure 2-48.
Serial Interface Circuit
2-53
Summary of Contents for LQ-2550
Page 1: ...L Q 2 5 5 0 TECHNICAL MANUAL EPSON ...
Page 240: ...REV A P r cl Figure 6 3 LQ 2550 Lubrication and Adhesive Application Points Diagram 2 6 3 ...
Page 241: ...REV A 7 i_ Figure 6 4 LQ 2550 Lubrication and Adhesive Application Points Diagram 3 6 4 ...
Page 252: ...REV A I 1 I 7 v m o m x b Figure A 6 PPD781OHG Block Diagram A 7 ...
Page 297: ...REV A 1 L I Irl N I i t 1 I I x Figure A 50 ROPSE Board Circuit Diagram A 52 ...