Table 1-3. Printer Select/Deselect (Dc1/Dc3) Control - Epson LX-HOO Technical Manual

NOTES 1. "Return" denotes a twisted pair return line connected to signal ground. When interfacing
the printer to the host, use twisted pairs for each signal. Shield the twisted pairs, and connect
the shield to GND in order to reduce interface.
2. All interface conditions are based on TTL levels. Both the rise and fall times of all signals
must be less than 0.2Ks.
3. Refer to the Parallel Interface Timing Chart for the timing of the signals.
4. Data transfer protocol must not ignore the ACKNLG or BUSY signal. (Data can be transferred
either after recognizing the ACKNLG signal or when the BUSY signal is LOW.)
5. The AUTO FEED XT and SLCT IN signals are valid when they are not fixed to LOW level by
the DIP switch or jumper.
6. Printing tests, including those of the interface circuits, can be performed without using
external equipment: set interface connector data lines 1-8 to the desired code (a floating
signal will be a logical 1, and a grounded signal will be a O) connect the ACKNLG signal
to the STROBE signal.
7. The PE signal is valid when the ERROR signal is LOW.
at Initialization
HIGH
LOW
Table 1-3. Printer Select/Deselect (DC—1/DC3) Control
I
I
DC 1
Printer
Select/Deselect
Select
Enable (Waits for a DC1. Input data is ig-
Deselect
nored until a DC 1 code is received.)
Select Enable
Select Enable
1-5
REV.-B
Data entry