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Profibus

Profibus products - 11614 A Dynamic Force in Industrial Automationand Controls

Power Supply Control Engine

Power Cordsets Pages 108-111 Molded Cordsets see Brad Harrison
® Designer’s Guide Network Interface see Industrial Communication Solution Guide Power Media Gateways Power is supplied to the active modules via a 5 pole Mini-Change Seamlessly transfers data in real time between dissimilar network protocols. Double-Ended Cordsets Pages 88-89 Data Media The main Profibus cable is of a shielded twisted pair design. It does not con- tain any conductors to power the Profibus modules or nodes, this is provid- ed through the power media. The connectivity for the active modules uses a shielded Brad Harrison reverse keyway, 5-pole connector design. The data connectivity is complemented with T-Splitters to connect the bus to the active modules and 9-pin D-sub connectivity for other Profibus compatible devices. Media

COMPONENTS AND ELEMENTS OF PROFIBUS SYSTEM

Network Interface Profibus uses a linear bus topology. At lower speeds it can be used with short drops from the main line to the active modules. Modules or nodes connected to the bus in this way can be ‘hot swapped’ without taking the bus off line. Unlike DeviceNet, the module or node power is not included in the bus media and has to be provided by separate connections. The scanner resides in the host controller whether it is a PLC or PC, providing a network connection. The scanner exchanges a data table, which is loaded with the various values of the inputs and outputs, with the logic controller to solve the various logical expressions. Simultaneously, the operation of the master and/or slave protocols is completed. The logical expressions are then re-exchanged with the data table for communication out to the various nodes and I/O residing on the network. The scanner generally supports all standard baud rates of the network. Control Engine PC “soft controllers” or PLCs can act as the main logic solvers, taking the current I/O status information of the network and solving these operations through the main control program. The new status of the I/O is then updated via the network interface to the actuators, starters and interface panels. Many times a central control engine often acts as the Profibus “master” which initiates and controls many of the messaging sequences of the network.
® connector.Two of the contacts are used to provide power to the module’s electronic cir- cuits and any input devices such as proximity switches. A separate and isolated power circuit is provided via another two contacts. This is used for output devices only and is not required on input only modules. This second supply should be controlled via the machine’s safety systems to ensure that no outputs are activated during operator interface with the machine.

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