PROFIBUS is a fast, open bus system widely used in automation technology. It is internationally standardized (IEC 61158 and EN 50170) and divided into three versions:
- PROFIBUS FMS (Fieldbus Message Specification) is used primarily for communication between controllers. FMS is supported by the Beckhoff BK3100 Bus Coupler (IP20 protection rating).
- PROFIBUS PA (Process Automation) is based on an intrinsically safe physical layer and is intended for process automation.
- PROFIBUS DP (Distributed Peripherals) is designed for fast data exchange at the sensor/actuator level.
The PROFIBUS devices in the Fieldbus Box series support PROFIBUS DP. Central control devices (such as industrial PCs or programmable logic controllers) communicate here over a fast serial connection with distributed input and output devices. Data is mainly exchanged cyclically, although acyclic services (DP V1) are also available for parameterization and diagnostics.
The high speed of PROFIBUS DP is most impressive: with a transmission rate of 12 Mbaud, less than 2 ms are needed to exchange 512 bits of input and 512 bits of output data with 32 bus devices. This satisfies the requirement for a short system reaction time.
The Beckhoff PROFIBUS devices have a powerful implementation of the protocol and are certified by PNO, the PROFIBUS Nutzerorganisation.
The Fieldbus Box modules for PROFIBUS DP are available as standard variant (B/C310) or optionally with integrated tee-connector (B/C318). This makes the fieldbus wiring much easier. The tee-connector that used to be necessary is replaced by a second M12-type fieldbus input/output. This makes the cabling more compact. Straight or angled versions of pre-assembled plugs or field-assembled plugs can be used.
Configuration
The node address is set in the range from 1 to 99 using two decimally coded rotary switches. The transmission rate is recognized automatically by the PROFIBUS box (auto baud rate). Device database files (*.gse) for PROFIBUS configuration tools are available. Special I/O parameters can be set by means of the KS2000 software or via acyclic DP V1 services.
Diagnostics
The extensive diagnostic functions of the Beckhoff PROFIBUS devices allow rapid fault localization. The diagnostic messages are transmitted over the bus and collated by the master. The status of the network connection, the device status, the I/O status and the status of the power supply are displayed by LEDs.
Compact Box
Compact Box modules for PROFIBUS DP are available for all relevant industrial signals. In addition to digital and analog input and output modules including thermocouple and RTD inputs, there are also incremental encoder interfaces available for displacement and angle measurement in addition to serial interfaces to solve a large number of communication tasks.
The Compact Box modules for PROFIBUS DP offer a wide range of I/O functionalities. All relevant industrial signals are supported. The digital inputs and outputs can be connected either with snap type 8 mm diameter plugs, screw type M8 or M12 connectors. For analog signals the M12 version is used.
Coupler Box
The PROFIBUS Coupler Box gathers the I/O data from the Extension Box modules over the interference-free IP-Link fiber-optic cable. It detects the connected modules and automatically allocates the input and output data to the process image. Both data consistency and a clear separation of input and output data are ensured. The Coupler Box has four digital inputs and four digital outputs. Other kinds of signals are available in the Extension Box.
The Coupler Box for PROFIBUS DP has four digital inputs and four digital outputs, optionally with snap type 8 mm diameter connectors, screw type M8 or M12 connectors. Up to 120 Extension Box modules can be connected via the IP-Link communication facility.
PLC Box
The PLC Box is an intelligent PROFIBUS node that can perform decentralized processing of I/O data and execute control tasks independently of the function of the PROFIBUS network. The PLC Box, like the Coupler Box, has four digital inputs and four digital outputs. Up to 120 further Extension Box modules can be connected via IP-Link. The I/O data can be made available either to the local PLC program or to the supervising controller. The PLC Box is programmed using TwinCAT over the PROFIBUS or through the configuration interface.
The PLC Box for PROFIBUS DP, programmable in accordance with IEC 61131-3, has four digital inputs and four digital outputs, optionally with snap type 8 mm diameter connectors, screw type M8 or M12 connectors. Up to 120 Extension Box modules can be connected via the IP-Link communication facility.