Siemens SIMATIC S7-1200 - Page 1091

Communication processor and Modbus TCP
13.3 Point-to-point (PtP) communication
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
1091
PtP Freeport over PROFIBUS or PROFINET
PtP enables you to use a PROFINET or PROFIBUS distributed I/O rack to communicate to
various devices (RFID readers, GPS device, and others):
● PROFINET (Page 804): You connect the Ethernet interface of the S7-1200 CPU to a
PROFINET interface module. PtP communication modules in the rack with the interface
module can then provide serial communications to the PtP devices.
● PROFIBUS (Page 968): You insert a PROFIBUS communication module in the left side
of the rack with the S7-1200 CPU. You connect the PROFIBUS communication module
to a rack containing a PROFIBUS interface module. PtP communication modules in the
rack with the interface module can then provide serial communications to the PtP
devices.
For this reason, the S7-1200 supports two sets of PtP instructions:
● Legacy point-to-point instructions (Page 1217): These instructions existed prior to version
V4.0 of the S7-1200 and only work with serial communications using a CM 1241
communication module or CB 1241 communication board.
● Point-to-point instructions (Page 1108): These instructions provide all of the functionality
of the legacy instructions, plus the ability to support PtP communication modules over
PROFINET and PROFIBUS distributed I/O. The point-to-point instructions allow you to
access the communication modules over the distributed I/O rack.
The S7-1200 CM 1241 modules must have a minimum firmware version of V2.1 to use
the point-to-point instructions. These modules are limited to the local rack to the left side
of the S7-1200 CPU.
Communications over distributed I/O use the following modules:
Station
Module
Article number
Interface
ET 200MP
CM PtP RS232 BA
6ES7540-1AD00-0AA0
RS232
CM PtP RS232 HF 6ES7540-1AB00-0AA0 RS232
CM PtP RS422/485 BA
6ES7540-1AD00-0AB0
RS422/RS485
CM PtP RS422/485 HF
6ES7540-1AB00-0AB0
RS232 and RS422/RS485
ET 200SP
CM PtP
6ES7540-6AA00-0BA0
RS232
Note
You can use the point
-to-point instructions to access local (or left side) serial modules, serial
modules over PROFINET and serial modules over PROFIBUS. STEP 7 provides the legacy
point
-to-point instructions only to support existing programs. The legacy instructions still
function, however, with the current S7
-1200 CPUs. You do not have to convert prior
programs from one set of instructions to the other.