Interface
12-5
CENTRONICS Parallel Interface
With this interface, 7 or 8 bit parallel data is accepted by the printer on a READY/BUSY closed
loop basis at data transfer rates of up to 100 kilobytes per second. When the printer is online
with a parallel data source, data is strobed into the printer one character at a time. A signal
from the printer acknowledges receipt of each character.
Parallel interface configurations that may be selected from the Printed Menu are as follows:
•
Busy indicated by busy lead and, optionally, by fault lead.
•
Select / deselect (online / offline) indicated by the busy lead or the fault lead
•
ACK pulsed during busy (not busy)
•
ACK inhibited for offline to online transition
•
ACK inhibited
on recovery
from paper-out condition.
•
ACK inhibited
on recovery
from fault condition
•
Lead polarity high or low for fault, select, paper out, ACK, busy, and strobe
•
Prime on received DEL (delete) code
•
Select/deselect by received DC1/DC3 codes
Parallel Interface Signals
DATA STROBE: Input from the data source used to transfer data into the printer logic.
Minimum pulse duration is 0.4 microseconds. Set STROBE polarity from the Printed Menu.
DATA BITS 1-8: Data byte to/from the data source. High level represents a binary 1 and low
level a 0. Data setup time is not necessary and the strobe pulse can be generated
concurrently with data.
ACKNOWLEDGE: A pulse that is generated by the printer to indicate receipt of a character.
Printed Menu options allow you to selectively enable or disable the pulse
on recovery
from
any fault, paper-out, or deselect state; to set the pulse polarity; and to set the position of the
pulse relative to busy.
