Handshaking Protocol; Establishing Communications; Verifying Communications - Bryce 9K-L User Manual

Handshaking
•
Protocol
Establishing
•
Communications
for IBM compatible
DOS systems
Verifying
•
Communications
Revision A
The Address Printer uses two methods of sending serial data,
XON/XOFF and DTR. The XON/XOFF software
handshaking uses only three wires of the cable, pins 2, 3 and
7. Software handshaking is performed by the printer when the
buffer is nearly ready to overflow. When the buffer has room
for only 100 more characters, the printer sends the host an
XOFF (ASCII DC3) character to signal it to stop data
transmission. The printer continues printing making more
room in the buffer. When the buffer has room for 150 more
characters, the printer sends the host an XON (ASCII DC1)
character to resume data transmission.
DTR is hardware handshaking in the Address Printer. The
printer uses a dedicated wire DTR (pin 20) for signaling the
host to start or stop data transmission. The printer accepts data
from the host until it has room for only 100 more characters.
The printer turns off DTR to the host device, indicating it to
stop data transmission. The printer continues printing making
more room in the buffer. When the buffer has room for 150
more characters, the printer turns on DTR, enabling the host to
resume data transmission.
The MODE command must be entered each time the computer
is turned on or it can be put into the autoexec.bat file for auto
loading. This command directs communications to the parallel
port and sets the computer for infinite retries so the computer
does not "time-out" while waiting for the printer to print. The
message "INFINITE RETRY ON PARALLEL PRINTER
TIME-OUT" will appear on your screen.
Use the following command for a Centronics Parallel
Interface.
•
Type: MODE LPT1:,,P and press ENTER
Use the following command for an RS-232-C Serial
Interface (at 9600 baud, no parity, 8 bits, 1 stop bit and
continuous retry on all time outs).
•
Type: MODE COM 1:9600,N,8,1,P and ENTER.
•
To verify that the computer and the printer are
communicating, make sure the printer is on-line, type
DIR>PRN and press ENTER.
9K-L USERS MANUAL
P/N 90-00860-001
Printer Menu System
Section 6 -
27