SIEMENS S7-1200 Communication for SIMATIC S7-1200 CM 1243-5

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The CM 1243-5 communication module is used to connect a SIMATIC S7-1200 to PROFIBUS as a DP master and has the following characteristics:

  • PROFIBUS DPV1 master in accordance with IEC 61158
  • Support of up to 16 PROFIBUS DP slaves
  • Communication with other S7 controllers based on S7 communication
  • Allows the connection of programming devices and operator panels with a PROFIBUS interface to the S7-1200
  • Module replacement without PG supported
  • Support of all standard baud rates from 9.6 Kbit/s to 12 Mbit/s
  • Compact industry-standard enclosure in S7-1200 design for mounting on a standard mounting rail
  • Fast commissioning thanks to easy configuration using STEP 7 without additional programming overhead

The CM 1243-5 is intended for use in factory automation. Low-cost PROFIBUS-based automation solutions can be created on the basis of the S7-1200 for optimal production.


PROFIBUS-based systems can be operated effectively for lower operating and maintenance costs:

  • Low costs since an automation solution requires no fixed wiring and less hardware
  • Fast response to faults thanks to excellent diagnostics options
  • Optimized plant and inventory management

The CM 1243-5 also offers further benefits especially for the requirements of micro-automation solutions:

  • Uncomplicated connection of the S7-1200 to PROFIBUS
  • Low-cost implementation of automation solutions based on PROFIBUS
  • Fast commissioning, as no programming overhead is required

Use of PROFIBUS-based micro-automation solutions enables optimal operation of the plant and problem-free production.

ApplicationCM 1243-5

The CM 1243-5 is designed for use in factory automation, particularly for mechanical engineering

With the CM 1243-5, low-cost, distributed automation solutions can be implemented on the basis of the S7-1200 , or in simple cases even complete plant automation systems. It can be used in all sectors of discrete automation. These include, for example:

  • Automotive
  • Pharmaceuticals
  • Semiconductors
  • Food processing industry

In mechanical engineering, the S7-1200 can be used with the CM 1243-5 as a central control unit, with sensors, actuators or the HMI devices connected direct via PROFIBUS.

  • Pick-and-place machines
  • Metalworking machines
  • Packaging machinery
  • Printing machines
  • Textile machines
  • Filling machines

The CM 1243-5 provides access to different communication services on the basis of PROFIBUS:

  • PROFIBUS DP (according to IEC 61158, master)
  • PG/OP communication
  • S7 communication


The CM 1243-5 works as a DP-V1 master in accordance with IEC 61158, handles data traffic completely autonomously, and thus relieves the CPU of communication tasks.

The data areas of the distributed I/Os are transferred consistently between CP and CPU. As a DP master, it allows the connection of up to 16 PROFIBUS-compliant DP slaves

PG/OP communication

The S7-1200 to which the CM 1243-5 is connected can be programmed with the help of PG/OP communication.

S7 communication

Communication with the following other systems can be implemented with the mechanisms familiar from the S7 world (Put/Get) on the basis of S7 communication:

  • To other SIMATIC S7 programmable controllers
  • To HMI devices
  • To PCs, laptops, field PGs with PROFIBUS cards


Extensive diagnostic options are available via STEP 7, including

  • Operating state of the CM
  • General diagnostics and statistics functions
  • Connection diagnostics
  • Message buffer

STEP 7 Basic V11 or higher is required for configuring the full functional scope of the CP 1243-5.