Siemens SIMATIC PG 720 P Manual page 101

Serial Port The serial port (COM1) on the PG 720 has the following pinout:
(PLC/RS-232/
Modem)
Figure 8-7
2
3
4
5
6
7
8
9
10
18
19
20
21
22
1
11-17
23-25
PG 720 P Programming Device
C79000-G7076-C721-02
COM1 Serial Port (Socket)
Pin No. Designation Description
TxD (D1) Serial transmit data
RxD (D2) Serial receive data
RTS (S2) Request to send
CTS (M2) Clear to send
DSR (M1) Data set ready
GND (E2) Ground (reference potential)
DCD (M5) Data carrier detect
+TTY RxD TTY receive
–TTY RxD TTY receive
+TTY TxD TTY send
+20mA Isolated current source
DTR (S1) Data terminal ready
–TTY TxD TTY send
RI (M3) Incoming call
– Shield
– Not assigned
– Not assigned
Hardware Information
1
14
25
13
Input/Output
Output
Input
Output
Input
Input
–
Input
Input
Input
Output
–
Output
Output
Input
–
–
–
8-13