Citizen Systems Compact desk-top dot matrix printer CBM-910 Type II - Manual (Page 28)

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POWER
DATA
STB
T1
DATA DATA DATA
T2
BUSY
ACK
T3
T1: 1.6
µs MIN
T2: 500
µS MIN
T3: 10
µs TYP
T4: 5
µs TYP
T5: 5
µS TYP
5.3 Description of Input/Output Signals
(1) Input signal
• DATA 1 to DATA 8 . . . 8 bit parallel signal (positive logic)
• STB . . . Strobe signal for reading out data (negative logic)
• RESET . . . Signal for resetting the entire unit (negative logic 4 ms or more)
(2) Output signal
• ACK . . . 8 bit data signal for requesting data. ACK is issued at the end of the
BUSY signal (negative logic)
• BUSY . . . Signal indicating the printer is busy. Input new data when the signal
is in “LOW” condition (positive logic)
• SELECT . . . Signal to indicate this equipment is in the SELECT (ready for
communication) state (positive logic)
“LO”is output in the state deselected by the operation panel (SEL-
SW), mechanical error, or memory error.
• P.N.E. . . . Signal to be output for paper-near-end
(3) Other
• GND . . . Ground commonly used in the circuit
• FRAME GND . . . Frame ground (case ground)
(4) Timing chart
Busy signal timing: Clear timing can be selected by the memory switch.
ACK signal timing: The following kinds of timing can be selected by the memory
switch setting.
BUSY
ACK
T4
BUSY
ACK
BUSY
Before
Center
After
ACK
T5