Siemens S7-1200 - Point-To-Point (Ptp) Communication

Communication processor and Modbus TCP
12.3 Point-to-point (PtP) communication
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
671
Table 12- 2 Termination and bias for the CB 1241
Terminating device (bias ON)
Non-terminating device (bias OFF)
①
Connect M to the cable shield
②
A = TxD/RxD - (Green wire / Pin 8)
③ B = TxD/RxD + (Red wire / Pin 3)
12.3
Point-to-point (PtP) communication
The CPU supports the following Point-to-Point communication (PtP) for character-based
serial protocols:
● PtP
● USS (Page 712)
● Modbus (Page 727)
PtP provides maximum freedom and flexibility, but requires extensive implementation in the
user program.
PtP enables a wide variety of
possibilities:
•
The ability to send information directly to an external
device such as a printer
•
The ability to receive information from other devices
such as barcode readers, RFID readers, third-party
camera or vision systems, and many other types of
devices
•
The ability to exchange information, sending and
receiving data, with other devices such as GPS
devices, third-party camera or vision systems, radio
modems, and many more
This type of PtP communication is serial
communication that uses standard UARTs t
o support a
variety of baud rates and parity options. The RS232
and RS422/485 communication modules (CM
1241)
and the RS485 communication board (CB
1241)
provide the electrical interfaces for performing the PtP
communications.