Parallel Interface (Option); Specifications; Signal Line And Pin Assignment - Citizen CL-E720DT Technical Manual

2-4-4. Parallel Interface (Option)

(1) Specifications

Transmission system 8-bit parallel data
Receive buffer size
Transmission modes
Signal level

(2) Signal line and pin assignment

Pin No. Signal name
1 STROBE
2-9 DATA0-7
10 ACKNLG
11 BUSY
12 PERROR
13 SELECT
14 AUTOFD
15 NC
16 SGND
17 FGND
18 P.L.H
19-30 GND
31 PRIME
32 FAULT
33 GND
34 NC
35 VCC
36 SELECTIN
16K bytes
Compatible mode
It is an asynchronous forward channel mode to send the byte width
data from the host to the printer. The interface line of the data is
operated in accordance with signal line definitions of Centronics.
NIBBLE mode
It is an asynchronous reverse channel mode to send the data from
the printer to the host. In Nibble mode, 4-bit data (half byte) is sent at
a time using the 4 status lines (FAULT, SELECT, PE, and BUSY). To
send one complete byte data, the printer sends 2 nibbles (8 bits in
total) to the host. Nibble mode is usually combined with Compatible
mode to create a complete bi-directional channel.
ECP mode
ECP mode permits bi-directional asynchronous data transmission,
and by means of interlock handshake, it does not require the timing
necessary with Compatible mode.
IEEE1284 compatible
I/O
Input Strobe signal to read in 8-bit data
Input 8-bit parallel signal
Output 8-bit data request signal
Output Signal specifying printer busy
Output Signal specifying media end
Output Signal specifying if the printer is on-line (printing enabled)
or off-line
Input Invalid (ignored)
--- Not used
--- Signal ground
--- Frame ground
Output Peripheral logic high (Pulled up to +5V at 10K resister.)
--- Ground for twisted pair return
Input Printer reset
Output Signal specifying printer error
--- Signal ground
--- Not used
--- Pulled up to +5V at 10K resistor.
Input Invalid (ignored)
2-57
Chapter 2 Operating Principles
Function in Compatible Mode
2-4. Interface
CL-E720DT