Parallel Interface; Bi-Directional Parallel Interface (Ieee 1284); Compatibility Mode; Reverse Mode - Citizen iDP-3221 Series User Manual

6.

PARALLEL INTERFACE

6.1

Bi-directional Parallel Interface (IEEE 1284)

6.1.1 Compatibility Mode (Host
(1) Outline
The familiar Centronics interface is used in the Compati bility mode.
(2) Specifications
Data transfer
Synchronization
Handshaking
Signal level
Connector
6.1.2 Reverse Mode (Printer
Status data may be transferred from the printer to the host in either the Nibble or Byte mode.
Outline:
It is assumed that data is transferred from an asynchronous printer controlled from the host.
The existing control lines are used in transferring data in the Nibble mode (transferred in 4-bit units
(nibbles)).
As simultaneous execution with the Compatibility mode is not possible, half-duplex communication is
employed.
Printer Communication Using the Centronics Interface)
: 8-bit parallel
: External nStrobe signal
: nAck and Busy signals
: All signals TTL compatible
: 57LE-40360 or equivalent (IEEE, 1284 Type B)
Host Communication)
Data is transferred in both directions on 8 data lines in the Byte mode (8-bit units (bytes)).
See Appendix 2 for details.
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