Epson DFX-8500 - Impact Printer, Service Manual

Page: 27 / 245

GENERAL DESCRIPTION
Rev. B
1-
19
1.3 INTERFACES
The DFX-8500 is equipped with parallel interface, serial interface, and optional Type-B interface card.
This section presents the specifications for each interface type.
1.3.1 Parallel Interface (Forward channel)
‰
Data transmission mode: 8-bit parallel, IEEE-1284 compatibility mode
‰
Synchronization: /STROBE pulse
‰
Connector type: 57-30360 (AMPHENOL) 36-pin plug or equivalent
‰
Handshaking: BUSY and /ACK handshaking
Notes 1: BUSY signal is set high before setting either /ERROR low or PE high and held high until
all these signals return to their inactive state. BUSY signal is at a high level in the following
cases.
„
During data entry (see data transmission timing)
„
When input data buffer is full.
„
During /INIT signal is at a low level or during hardware initialization
„
During printer error (see /ERROR signal)
„
During test printing or during setting printing
„
During SelecType
„
When the parallel interface is not selected.
Notes 2: /ERROR signal is at a low level when the printer is in one of the following states.
„
Printer hardware error (fatal error)
„
Paper out error
„
Paper jam error
„
Cover open status
„
Incomplete paper change
„
Paper size error
„
Ribbon jam error
Notes 3: PE signal is at a high level during paper out error.
‰
Data transmission timing: Refer to Figure 1-21.
Parameter Minimum Maximum Parameter Minimum Maximum
t setup 500 ns --- t ack 500 ns 10 us
t hold 500 ns --- t nbusy 0 ---
t stb
500 ns ---
t next
0 ---
t ready
0 ---
tt-out*
--- 120 ns
t busy --- 500 ns tt-in** --- 200 ns
t reply --- ---
Note: * Rise and fall time of output signals
** Rise and fall time of input signals.
Figure 1-21. Data Transmission Timing
D A T A
S T R O B E
B U S Y
A C K N L G
t s e t u p
t r e a d y
t b u s y
t s t b
t r e p l y t a c k t n b u s y
t n e x t
t h o l d
D A T A ( n )
D A T A ( n + 1 )