Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 32)

Using the Serial Ports
Chapter 4
4–8
The peripheral port is an asynchronous serial communication channel
compatible with RS-423A/232C or RS-422 interfaces. It uses bi-directional
XON/XOFF software handshaking and RTS/CTS, DTR, DSR, DCD
hardware handshaking for interfacing with printers, terminals and
commercial asynchronous modems. Use a CALL routine to change
peripheral port configuration. Configure the baud rate (300 to 19.2K bps)
by setting a configuration plug. Refer to figure 3.2 for configuration plug
locations.
In addition, the peripheral port has the following format requirements:
configurable parity: odd, even or none
fixed start bits: 1
configurable stop bits: 1, 1.5 or 2
configurable data bits: 5,6,7 or 8
receiver threshold: 200 mV
driver output (loaded): +3.6V
Defaults are 1 start bit, 1 stop bit, 8 bits/character, no parity, handshaking
off and 1200 baud.
When you select 8 bits/character you have full access to all 8 bits of each
character on both input and output data bytes.
Refer to figure 4.2 for peripheral port wiring connections.
The peripheral port can connect to printers (figure 4.6), asynchronous
modems and to SA/SB recorders for program storage and retrieval (figure
4.7).
Figure 4.6
Cable Connection to 1771-HC Printer
4.4
Peripheral Port