Toshiba B-570 SERIES Owner's Manual page 45

1. OUTLINE OF THE SYSTEM
2 Centronics interface
(1) Data input method:
(2) Control signals:
(3) Data input code:
(4) Receiving buffer:
(5) Input/Output crcuit configuration and Input/Output conditions
Type
Input
Output
3 External I/O interface
(1) Interface circuit
Input circuit
There are five input circuits, and each input is a current loop using a photo-coupler. The anode of the
photo-coupler is connected to common pin COM1 in each of the five circuits. Each cathode is
independent. The voltage of Vcc is 24 V (max.) while the diode operating current is 16 mA.
8-bit parallel (DATA 1 ~ 8)
ACK, BUSY, PAUSE, DATA;STB, INPUT; PRIME, FAULT, PE
ASCII, JIS 8-bit code for European characters, 8-bit code for graphic
5KB
Signal Name
DATA 1 ~ 8
INPUT•PRIME
DATA•STB
SN7406 or equivalent
BUSY
FAULT
PAUSE
ACK
PE
Printer
Photo-coupler
TPL521 (TOSHIBA)
Configuration
SN74LS14 or equivalent
+5V
1K
+5V
SN74LS14 or equivalent
1K
100P
COM1
IN0
IN4
1-9
1.5 ELECTORONICS SPECIFICATIONS
Logical level (input)
"1" = 2~5 V
"0" = 0~0.4 V
+5V
Logical level (input)
1K
"1" = 2.4~5 V
"0" = 0~0.4 V
100P
External controller, etc.
Vcc
R
R
EM10-33006A
Fig. 1-7
Fig. 1-8