science

SafetyBUS p

SafetyBUS p is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand SafetyBUS p rather than just read about it. In short: SafetyBUS p is a standard for failsafe fieldbus communication in automation technology. It meets SIL 3 of IEC 61508 and Category 4 of EN 954-1 or Performance Level "e" of the successor standard EN 13849-1.

Key takeaways

SafetyBUS p belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SafetyBUS p to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SafetyBUS p from memory before moving on to harder problems.

Reference excerpt

SafetyBUS p is a standard for failsafe fieldbus communication in automation technology. It meets SIL 3 of IEC 61508 and Category 4 of EN 954-1 or Performance Level "e" of the successor standard EN 13849-1.

Origin SafetyBUS p was developed by Pilz GmbH & Co. KG between 1995 and 1999. The objective was to provide a fieldbus for data communication in terms of machinery safety . Since 1999 the technology of SafetyBUS p has been managed by the user organisation Safety Network International e.V. (formally SafetyBUS p Club International e.V.), whose members work on the further development of SafetyBUS p.

Application The main application of SafetyBUS p lies in the communication of data with safety-related content. SafetyBUS p can be used anywhere that communicated data has to be consistent in terms of time and content, in order to safeguard against danger. This danger may concern hazards to life and limb, but may also involve the protection of economic assets. Typical application areas are:

Factory automation (e.g. car production, presses) Transport technology (e.g. cable cars, fairground rides) SafetyBUS p can be used on applications with safety-related requirements up to SIL 3 of IEC 61508 or Cat. 4 of EN 954-1.

Technology Technically, SafetyBUS p is based on the fieldbus system CAN. In addition to OSI Layers 1 and 2, which are already defined in CAN for bit rate and security, SafetyBUS p adds additional mechanisms to safeguard transmission in Layers 2 and 7.

Fault mechanisms The following mechanisms are used on SafetyBUS p to detect transmission errors and device errors:

Sequential numbers Timeout Echo ID for transmitter and receiver Data security (cyclic redundancy check)

Technical details The SafetyBUS p frame data, as determined by the technology, is as follows:

Maximum 64 bus subscribers per network Up to 4000 I/O points per network Transmission rates 20 to 500 kbit/s, depending on the network extension Individual network segments can extend to up to 3500 m Multiple network segments can be connected Guaranteed error reaction times of up to 20 ms can be achieved Suitable for applications in accordance with SIL 3 of IEC 61508 and Cat. 4 of EN 954-1 Option to supply voltage to the devices via the bus cable Subnetworks can be implemented in wireless technology, with fibre-optic cables and as an infrared connection.

Devices Only safety-related devices are used in SafetyBUS p networks. In general these are designed to be multi-channel internally. Safety-related use of the devices normally requires safety to be certified by authorised testing laboratories, who test the devices in accordance with the applicable standards and provisions. A functional inspection is carried out by the user organisation Safety Network International e.V.

Organisation The user organisation SafetyBUS p Club International e.V. combines manufacturers and users of SafetyBUS p and has been in existence since 1999. In 2006 the organisation was renamed Safety Network International e.V. In addition to the international organisation there are also two other regional organisations: Japan was established in 2000, while USA was established in 2001. The organisation continues to develop the system, resulting in its successor, SafetyNET p.

Literature Winfried Gräf: Maschinensicherheit. Hüthig GmbH & Co. KG, Heidelberg 2004, ISBN 3-7785-2941-2 Armin Schwarz und Matthias Brinkmann: Praxis Profiline – SafetyBUS p – Volume D/J/E. Vogel Industrie Medien GmbH & Co. KG, Würzburg 2004, ISBN 3-8259-1919-6 Armin Schwarz und Matthias Brinkmann: Praxis Profiline – SafetyBUS p – Volume D/E. Vogel Industrie Medien GmbH & Co. KG, Würzburg 2002, ISBN 3-8259-1915-3 EU machinery directive: 98/37/EG IFA Report 2/2017: Funktionale Sicherheit von Maschinensteuerungen – Anwendung der DIN EN ISO 13849 BG ETEM, Prüfgrundsatz GS-ET-26: Bussysteme für die Übertragung sicherheitsrelevanter Nachrichten Reinert, D.; Schaefer, M.: Sichere Bussysteme für die Automation. Hüthig, Heidelberg 2001. ISBN 3-7785-2797-5

External links Organizations:

Safety Network International e.V. Safety Network International USA (Regional organization for USA)

Worked examples

Example 1 — a first encounter with SafetyBUS p

Start with the simplest possible case. Write down what SafetyBUS p claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to SafetyBUS p before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about SafetyBUS p ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of SafetyBUS p

In research: SafetyBUS p appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses SafetyBUS p in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: SafetyBUS p is common in secondary-school and first-year university syllabi. It links to neighbouring topics Industrial automation, Safety, so understanding it makes those chapters shorter.
In everyday life: Look for SafetyBUS p outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study SafetyBUS p in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SafetyBUS p means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain SafetyBUS p out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SafetyBUS p in simple terms?

Why does SafetyBUS p matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study SafetyBUS p?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on SafetyBUS p.