Interview Questions

Profibus Interview Questions and Answers

Profibus is a vital fieldbus communication standard in automation, ensuring seamless interaction among devices. Here, we address essential questions for a concise understanding of this key industrial communication protocol.

Profibus Interview Questions and Answers Part 1

In the field of automation, Profibus is a standard for fieldbus communication that enables communication between systems and devices on the same network.

Profibus-PA (Process Automation), which is used in hazardous situations and for process automation, and Profibus-DP (Decentralized Periphery), which is utilized for high-speed communications, are the two variants.

The objective of Profibus’s design was to give industrial control systems a reliable and effective communication method. It is unique in that it is deterministic and supports both high-speed and process automation applications.

Profibus-DP has a maximum data rate of 12 Mbit/s.

A single master and up to 126 devices can be supported on a single Profibus network.

On the bus, the master regulates communication. Slaves reply to its requests by sending them messages.

It is possible for multiple masters to coexist and monitor their individual slaves in multi-master systems supported by Profibus.

On the Profibus network, a device that complies with requests from the master is called a slave. Communication cannot be initiated by slaves.

A GSD (General Station Description) file contains information on the characteristics and functionalities of a device. It is necessary in order to configure a network using Profibus.

PROFIBUS is a serial communication protocol, and PROFINET is an Industrial Ethernet protocol: Both are industrial communication standards

For maintenance and troubleshooting in Profibus networks, ProfiTrace is an effective tool. It makes network testing, monitoring, and analysis possible.

Cyclic Redundancy Check (CRC) is a technique used by Profibus to identify errors in data that is transmitted.

Profibus is deterministic since data is transmitted at predetermined times, ensuring reliable and consistent communication.

Profisafe is a Profibus and Profinet profile that specifies safety-related communication.

Profibus-PA supplies power and communication over the same pair of wires using a method known as Fieldbus Intrinsically Safe Concept (FISCO).

In order to eliminate signal reflections, resistors should be used to terminate a Profibus network at both ends.

The baud rate determines the maximum length. A segment up to 1200 meters can be had at the slowest speed (9.6 Kbps). A maximum of 100 meters can be covered at the fastest speed (12 Mbps).

On a Profibus network, every device is assigned a unique address that falls between 0 and 125. The master has reserved address 126.

Tools such as ProfiTrace are useful for problem diagnosis. Moreover, many Profibus devices contain diagnostic registers providing information on errors and conditions.

In order to build a branch inside a Profibus network or to increase the length of an existing network, a repeater is utilized.

In a wide variety of industries, including manufacturing, process control, and automation, Profibus is utilized for a variety of activities, including monitoring temperature, pressure, flow rate, and other related parameters.

To link a device to the Profibus network, utilize a Profibus connection. To enable or disable the bus termination, it usually has a termination switch.

The network status is shown visually by the LEDs. They can display information on the network’s activity, the transfer and reception of data, and error rates.

Profibus provides predictable, reliable, and efficient communication. Additionally, it supports a large range of devices and is highly scalable.

Because Profibus employs a token-passing protocol, communication can only begin by the master device that has the token, preventing collisions.

Fields for synchronization, recipient address, control information, data, and error checking are all included in a Profibus telegraph.

Communication between a Profinet network and a Profibus network is made possible by a Profibus proxy.

Process automation is the focus of Profibus-PA, which also provides integration with Profibus-DP, power and communication over the same wire, and intrinsic safety for hazardous areas.

When a device is swapped out, the master will automatically detect the new one, avoiding the need for reconfiguration.

Many data types, including Boolean, Byte, Word, Double Word, and Real, are supported by Profibus.

A device that executes the commands of the DP master in a Profibus DP network is known as a slave. It is unable to initiate communication.

Depending on the Profibus version being used, shielded twisted pair cables are usually utilized for Profibus networks.

The group that supports and advances the Profibus and Profinet technologies is called Profibus International. It is in charge of training, certification, and standardization.

Yes, Profinet and Profibus networks may communicate to one another through the use of a proxy.

Data requests and commands are sent by a Profibus DP master, which also manages communication with the DP slaves.

In Profibus, synchronization is achieved by precisely timing the transfer of data and utilizing a master clock.

The Profisafe profile for safety-related communication is supported by Profibus. In order to ensure data integrity, it also has error detection systems.

A Profibus network profile is a specification that details the characteristics and actions of a specific class of application or device within the network.

An advanced communication protocol called Profibus FMS (Fieldbus Message Specification) is utilized for communication between equal partners. Profibus DP is designed to exchange I/O data at high speeds in a cyclic fashion.

Diagnostic registers on Profibus devices are able to detect problems with the network. Redundancy is also used by some networks for important purposes.

Several devices, including as PLCs, sensors, actuators, drives, and more, can be connected.

Software tools are used to set up devices, and the manufacturer’s GSD file is used to establish the device parameters.

Profibus ensures timely transmission of data by utilizing a token-passing system.

With only three layers—the Physical Layer (1), Data Link Layer (2), and Application Layer (7)—Profibus employs a condensed version of the OSI paradigm.

Diagnostic features on Profibus devices allow them to report malfunctions. Redundancy may be utilized in specific circumstances to guarantee ongoing operations.

A Profibus coupler is used to join two Profibus network segments together. This is frequently done to increase the network’s coverage area or to join Profibus-PA and Profibus-DP segments.

In order to ensure that data is sent and received at exact, consistent intervals, Profibus uses its deterministic nature to manage real-time data.

A common interface for a range of drives is provided by ProfiDrive, a Profibus profile specifically created for drive technology.

A Profibus network segment is an area of the network that is connected continuously—that is, without interruptions from repeaters or other devices—by cables.

The method of having backup devices or networks in place to ensure continuing functioning in the event of a failure is known as profibus redundancy.

Click here Profibus Interview Questions and Answers Part 2

Sundareswaran Iyalunaidu

With over 24 years of dedicated experience, I am a seasoned professional specializing in the commissioning, maintenance, and installation of Electrical, Instrumentation and Control systems. My expertise extends across a spectrum of industries, including Power stations, Oil and Gas, Aluminium, Utilities, Steel and Continuous process industries. Tweet me @sundareshinfohe

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