Epson DFX-8500 service manual Interfaces, Parallel Interface Forward channel

GENERAL DESCRIPTION

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.

		D A T A		( n )	D A T A	( n + 1 )
D A T A
		t	h o ld
S T R O B E
		t	s t b		t n e x t
t
	s e t u p
B U S Y
	t	r e a d y
A C K N L G t b u s y
			t r e p ly		t a c k t n b u s y

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

Rev. B 1-19