Program port, 3 program port – Rockwell Automation 1771-DB Basic Module User Manual - Series A User Manual
Page 27
Using the Serial Ports
Chapter 4
4–3
The program port is an RS-423A/232C compatible serial port that provides
minimum signal line connection to terminals, printers and other serial
devices for operator-program interaction, command level input, printer
output etc. Figure 4.2 shows the signals available on both the program port
and the peripheral port described later.
Figure 4.2
Program Port and Peripheral Port Wiring Connections
Program Port
Peripheral Port
Description
1
1
1
1
Chassis/Shield
2
1
2
1
TXD-Output
3
1
3
1
RXD-lnput
4
4
1
RTS-Output
5
5
1
CTS-lnput
6
6
1
DSR-lnput
7
1
7
1
Signal Common
8
8
1
DCD-lnput
9
9
1
Signal Common
10
10
1
Signal Common
11
11
NC
12
12
NC
13
13
NC
14
14
1
RS-422 TXD
15
15
NC
16
16
1
RS-422 RXD
17
17
NC
18
18
1
RS-422 RXD’
19
19
NC
20
20
DTR-Output
21
21
NC
22
22
NC
23
23
NC
24
24
NC
25
25
1
RS-422 TXD’
1
Signal is provided on this pin
The baud rate is initially set at 1200 baud. You can use CALL 78 to change
the baud rate from 300 to 19.2K bps.
The program port has the following fixed format:
parity: none
start bits: 1
stop bits: 1
data bits: 8
receiver threshold: 200 mV
driver output (loaded): +3.6V
4.3
Program Port