Specifications

Operation Manual 3. Interface Specification
DR300 33
data. When it is placed back on line manually, it sends an X-On,
indicating it is again available for receipt of data. If an error occurs
during printing (paper out, ribbon out), the printer sends nothing in
the Single Job Buffer mode since the last character transmitted was
an X-Off. When the error is cleared and the printer resumes print-
ing, no X-On is sent until the current job is completed and the
printer is once again read to receive the next job. If it is in the Multi
Job Buffer mode, it sends an X-Off as soon as an error condition
is detected. When the error is cleared and the printer is placed
back on-line, it transmits an X-On indicating it is again ready to
accept data.
Upon switch up, if no error conditions are present, the printer will
continually send X-On characters at five millisecond intervals until
it receives a transmission from the host.
Cable Requirements
Bi-Directional Communications
This is a two-way communications protocol between the host com-
puter and the printer, thus enabling the host to check printer status.
When this protocol is selected, there is no busy signal from the
printer (pin 20, DTR, is always high). The host must request the
complete status from the printer, including ready/busy. Whenever
the host requests printer status, it transmits an ENQ to the printer
and the printer will respond with its status within five milliseconds.
If printing, it will respond upon finishing the current label, then
resume printing. In order for this protocol to work properly, pin 6
(DTR) and pin 5 (CTS) must be held high by the host. One way to
ensure these pins are always in the correct state is to tie pin 20
HOST INTERCONNECTION PRINTER
FG 1 FG (Frame Ground)
RD 2 TD (Transmit Data)
TD 3 RD (Receive Data)
4 RTS (Request to Send)
5 CTS (Clear to Send)
6 DSR (Data Set Ready)
20 DTR (Data Terminal Ready)
SG 7 SG (Signal Ground)