Diese Unterlagen sind als informierende, schulungsbegleitende Unterlagen erstellt worden, sind aber auch teilweise zum Selbststudium geeignet. Diese Unterlagen sind nach bestem Wissen und Gewissen erstellt. Wir übernehmen keine Haftung für etwaige Fehler. Ebenso übernehmen wir keine Haftung für etwaige daraus resultierende Schäden oder Mangelfolgeschäden. Nur für den internen Gebrauch! Diese Unterlage ist nur für KRONES - Servicepersonal bestimmt! Bei Fragen oder Anregungen stehen wir Ihnen gerne zur Verfügung. ____________________________________________________________________ This documentation was created as an informatory, training supplementary document. It is also suitable for self-studying. This documentation was created to the best of our knowledge. We assume no liability for possible mistakes. We also assume no liability for potentially resulting disadvantages or complications. For internal use only! This documentation is for KRONES Service only! If you have any further questions or suggestions please don’t hesitate to contact us. Krones AG KD Trainingscenter Serviceengineering (TCSE) Böhmerwaldstraße 5 93073 Neutraubling Trainingcenter.service@krones.com 1 Table of contents What is a field bus?.......................................................................................................3 Sections of automation.......................................................................................4 The levels of the field bus............................................................................................5 Network topologies............................................................................................8 The field cable..............................................................................................................13 EMC.................................................................................................................................14 Training centre, service engineering 2 Notes Training centre, service engineering 3 Plant automation Transport technology, warehousing technology, and handling technology for discrete parts, installation and packaging lines, robots, machine tools. Process automation Transport, warehouse and processing of liquids, gases or bulk goods, food and feeding stuff processing and packaging, pharmaceutical, chemical and petrochemical industry. Building automation Heating, fan and ventilation in buildings, light control, emergency systems, control systems, lifts. Training centre, service engineering 4 Typical sensors: Simple control devices, buttons, selection switch, P.E. cells, inductive, capacitive, optical and ultrasonic proximity switches, fill level indicator, thermal protector. Typical actuators: Pneumatic valves, hydraulic valves, pilot lamps, acoustic warning units, simple electrical drives, control valves. Training centre, service engineering 5 Typical sensors: Pressure transmitters, flow transmitters, and temperature transmitters, fill level measuring devices, devices for determining chemical and physical properties, absolute linear measuring devices for angle of rotation. Typical actuators: Pneumatic and hydraulic proportional valves, speed-controlled drives. Training centre, service engineering 6 Notes Training centre, service engineering 7 The topology or structure of the field bus network defines how the individual components of the automation system are connected with each other. This electrical connection can be set up using different methods. If the goal of the field bus use is to reduce working costs, choosing the right topology is of crucial importance! The topology questions also include • The maximum possible number of stations which can be connected to a network. This number can be further split up into the number of stations which can be connected both physically and logically. • The maximum distance which can be bridged with the field bus. This number can once again be subdivided into the maximum distance between the master and one slave and two slaves in a network. • The possible use of repeaters and other structure components to allow particular topologies to be set up. Training centre, service engineering 8 With star topologies, the master, the reception, is connected with each field device via a two-point connection. This corresponds with the parallel wiring of each device with the controller as common up to now. The information, i.e. the sensor messages and the control commands are usually only transmitted in one direction. Training centre, service engineering 9 With ring topologies, the master, the reception, is connected with two field devices via a two-point connection. The field devices are connected in a row with each other. Thus, a ring structure is established. Here, the communication passes through each station in one direction. It assumes the function of an intermediate amplifier or of a repeater. In each station, an output information is replaced by an input information and the entire telegram is transmitted like in a distributed shift register. Training centre, service engineering 10 If all stations are connected electrically parallel to a shared line, a line structure is generated. This topology is also known as bus topology. Training centre, service engineering 11 At the tree structure, all stations are connected electrically parallel just like with the line structure. Here, the length of all spur lines are not limited, it is even possible that branches are going out of branches. Terminating resistors are not planned. •All stations are connected electrically parallel to a shared line •Contrary to the line structure, there is no limit for the spur line length •No use of terminating resistors •The largest-possible freedom to adjust the network to the local conditions •All stations take part in the communication •additional rules for a trouble-free communication is required Training centre, service engineering 12 Notes Training centre, service engineering 13 Fault emission The field bus as a total, or its components must not cause interruptions on other components. Radiation limit values are defined in the corresponding standards which are approved for the use in an industrial environment (class A) or residential areas (class B). Resistance to electrostatic discharge In dry environments, there is the danger of electrostatic discharge which is favoured by insulated floor surfaces, non-conducting bulk goods, not grounded conveyors and similar factors. Electrostatic discharge must not have negative effects on the proper function of the field bus components. HF fields High-frequency electromagnetic fields have different forms of appearances. They can be line-independent up to frequencies of approx. 80MHz; furthermore, they can influence field bus components as amplitude and phase modulation. Sources of faults can be, for example, radios, broadcasting stations, transformers. Induced interference voltages Interference voltages can be induced via parallel lines of frequency inverters. Training centre, service engineering 14 Training centre, service engineering 15 Diese Unterlagen sind als informierende, schulungsbegleitende Unterlagen erstellt worden, sind aber auch teilweise zum Selbststudium geeignet. Diese Unterlagen sind nach bestem Wissen und Gewissen erstellt. Wir übernehmen keine Haftung für etwaige Fehler. Ebenso übernehmen wir keine Haftung für etwaige daraus resultierende Schäden oder Mangelfolgeschäden. Nur für den internen Gebrauch! Diese Unterlage ist nur für KRONES - Servicepersonal bestimmt! Bei Fragen oder Anregungen stehen wir Ihnen gerne zur Verfügung. ____________________________________________________________________ This documentation was created as an informatory, training supplementary document. It is also suitable for self-studying. This documentation was created to the best of our knowledge. We assume no liability for possible mistakes. We also assume no liability for potentially resulting disadvantages or complications. For internal use only! This documentation is for KRONES Service only! If you have any further questions or suggestions please don’t hesitate to contact us. Krones AG KD Trainingscenter Serviceengineering (TCSE) Böhmerwaldstraße 5 93073 Neutraubling Trainingcenter.service@krones.com 16
