Introduction to INTERBUS

INTERBUS The open fieldbus system INTERBUS for modern automation uniformly links all the process peripherals with all common controllers. With the serial bus cable, it is possible to network sensors and actuators, control machines and systems, network production cells and connect higher-level systems, such as control rooms.

As far as its topology is concerned, INTERBUS is a ring system, i.e. all stations are actively connected within an enclosed transmission path. Each device refreshes the incoming signal and forwards it. Compared to other ring systems, the outgoing data line as well as the return line within a cable are led through all devices in the INTERBUS system. This results in the physical appearance of a line or tree structure. A main artery leads off from the bus master, from which subsystems for structuring the entire system can be created. In this way, the bus system can be configured to suit every application.

• Active ring
• Master slave, fixed telegram length, deterministic ring; every remote bus device is a repeater
• Transmission rate: 500 Kbit/s
• Max. 4096 I/O points
• Length of bus: 400 m (between two remote bus devices) total length 13 km
• Typ. areas of application: Sensor and actuator systems in general, mechanical and plant engineering, process engineering

Due to the point-to-point connection, there is no need to install terminating resistors. The system can be flexibly adapted to user requirements by adding or removing a device. Numerous topologies are possible. Special bus terminal modules create branches that allow the connection and the decoupling of devices. The coupling elements between the bus segments allow subsystems to be enabled and disabled and therefore make working at a low-level system possible, for example in the case of an error or when systems need to be extended.

Data is not assigned to the individual stations, as is required in other systems by assigning a bus address with DIP or rotary switches in the individual stations. Instead, data is assigned automatically by means of the physical position of the stations in the system. This plug and play function is a decisive advantage with regard to reducing the installation complexity and increasing the ease of maintenance of the system. The problems and possible malfunctions that might occur through manual setting of the device address during installation and service are often underestimated.