What is the purpose of DP DP coupler?

The DP DP coupler is used for connecting two Profibus networks with each other for enabling data transmission amongst the controllers of both the Profibus networks. For input and output transmitted data, the utmost length is of 244 bytes.

The outlining of the DP DP coupler is done using a software design tool that assimilates the coupler using a GSD file.



What are the properties of DP DP coupler?

  • Dual power supply
  • Electrical isolation between the DP networks
  • Different transmission rates and Profibus addresses on both sides of the coupler
  • DP1 is supported with uniform and full diagnostic functioning
  • It is robust. That means even if one side fails, it will retain the output values of the other side
  • Offers up to 16 input/output areas for data transmission
  • Of the 244 bytes of input and output data exchanged, 128 bytes are consistent
  • Easy to set up the Profibus addresses using software or DIP switches
  • Profibus-DP up to 12 Mbps
  • Automatic baud rate recognition

For safety reasons, the DP DP coupler can be coupled with two different power sources concurrently.

The DP DP coupler allows the Profibus to rapidly transfer the processed data between the decentralized field modules like drives or slaves and central controller modules like PC or PLC.

During normal operation, the central controller cyclically reads the input of the connected decentralized field modules for sending the output data to them. The maximum of 244 bytes of output and input data can be transferred in one cycle.

Apart from the user data traffic, the DP DP coupler offers wide-ranging diagnosis and authorizing functions. The current diagnosis messages of the decentralized modules are summarized in the central controller modules. This enables a rapid localization of errors.  

Features of Profibus-DP

  • Bus length up to 100 meters at 12 Mbit/s and up to 1200 meters at 9.6 kbit/s
  • An optical fiber or twisted pair cable as a medium for bus
  • Up to 126 subscribers with repeaters (one bus) and 32 subscribers without repeaters
  • Integrated repeater controller
  • Synchronization of outputs and inputs through control commands


The DP DP coupler ensures the independence of both the Profibus networks. That means you need to configure an individual Profibus address for every Profibus-DP network.   

It is crucial to comply with the accident prevention and safety regulations like machine protection guidelines when using the Profibus-DP. Certain equipment must retain an operational state in all operating modes.


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