Many roads lead to the bus

Network components ensure the necessary flexibility of installation.

The efficient automation of machines and plants is hardly possible nowadays without using fieldbus technology. Modular automation terminals and fieldbus-specific infrastructure components are the major components for simple and cost-effective installation concepts.

Star and tree structures for Profibus?


Profibus allows the following installation parameters:
  • A maximum of 32 devices per segment
  • Only line structure permitted
  • Maximum 1200 m conductor length (depending on the transmission rate)
  • Conductor termination necessary
  • Passive branch line permitted to some extent, max. 3 m length




Using repeater components gets around these restrictions, increases the performance and availability of the bus system and cuts installation costs. Any number of branches in star and tree structures allow the installation to be adapted to the local conditions. Other advantages for the user:
  • Extending the number of devices to n x 32 (maximum 127)
  • Multiplying the permitted cable length
  • Increasing the transmission speed
  • Maximum exploitation of the Profibus specification in every segment.




The Profibus repeater of the new PSM-ME series is 22.5 mm slim, can simply be snapped onto the DIN rail and supplied with 24 V DC/AC. Parasitic voltages are avoided by putting the 2 kV 3-way isolation between the two interfaces and the supply voltage. The integrated protective circuit provides additional safety and directs transients automatically to ground potential.



Networking with fiber optics


Even though the use of repeaters solves many problems in both transmission and structure, the physical possibilities of copper-based transmission remain limited. Where there are extreme EMC influences, for example, fiber optics is advisable.

The main elements for any FO network are the T-couplers that realize a conversion of the bus interface to two ports. The PSI-MOS series has been specially designed for industrial requirements in the control cabinet. It is a range of FO T-couplers and terminal devices in polymer, HCS and fiber glass for interference-free networking of Profibus devices. Active bit retiming and as a consequence, unrestricted cascading depth, permanent fiber break monitoring with a floating fault warning output and an uncomplicated FO connection system are the particular features of these products.




Fast and easy installation for Profibus devices


The new "Subcon-Plus-Profib" quick mounting connectors have been designed to connect devices in the Profibus system with up to 12 Mbit/s. Using the quick stripping tool, the connection takes less than a minute with screw and spring-cage terminals, with a choice of axial or angled cable entry and even with a programming interface on request. The integrated terminating resistor can be activated externally, disabling the outgoing bus segment.



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