What is the Difference between Profibus and Profinet?

Summary

The video script provides a detailed comparison between two industrial communication protocols, Profibus and Profinet, both widely used in Siemens control systems. Profibus, released in 1993, is a well-established protocol with over 50 million devices installed by the end of 2017. It uses a DB-9 serial connector, identifiable by its purple cable and unique addressing system. Profibus operates at speeds from 9600 bits per second to 12 megabits per second, with cable lengths up to 1000 meters but requiring shorter lengths for higher data rates. On the other hand, Profinet, a newer Ethernet-based protocol, uses standard RJ-45 Ethernet jacks and green-colored cables, designed for harsh environments. It operates at 100 megabits per second with a response time of less than 1 millisecond, making it ideal for high-speed applications. Profinet devices have three types of addresses: IP, MAC, and a unique device name. The video emphasizes the growing preference for Profinet due to its higher speed and flexibility, and the importance for automation engineers to be familiar with both protocols.

Takeaways

• 📈 Profibus and Profinet are distinct industrial communication protocols used by Siemens control systems.
• 🔌 Profibus utilizes a DB-9 serial connector and is identifiable by its purple cable jacket, while Profinet uses an RJ-45 Ethernet jack and green cables.
• 🔄 Profibus allows daisy-chaining with pass-through ports on some connectors and requires a terminating resistor for proper network operation.
• 📊 Each device on a Profibus network must have a unique address from 1 to 127, supporting a maximum of 127 devices on one network.
• 🚀 Profibus operates at speeds ranging from 9600 bits per second to 12 megabits per second, with cable lengths varying based on data rates.
• 🌐 Profinet is an Ethernet-based protocol, offering high-speed operation at 100 megabits per second with a response time of less than 1 millisecond.
• 🏗 Profinet is suitable for harsh industrial environments and can be expanded using standard Ethernet switches.
• 📍 Profinet devices have three types of addresses: IP address, MAC address, and a unique device name, with automation engineers focusing on device names and IP addresses.
• 🔑 Profinet is becoming the preferred protocol for industrial applications due to its higher speed and flexibility.
• 🤝 Familiarity with both Profibus and Profinet is crucial for a controls engineer's role.
• 📚 For career advancement in PLC programming and understanding industrial communication protocols, resources like realpars.com can be beneficial.

Q & A

What are the key differences between Profibus and Profinet protocols?

Profibus and Profinet are both industrial communication protocols used by Siemens control systems. Profibus, released in 1993, is an older technology with over 50 million devices installed by the end of 2017, operating at speeds from 9600 bits per second to 12 megabits per second. It uses a DB-9 serial connector and purple cables. Profinet, on the other hand, is a newer Ethernet-based protocol with a standard RJ-45 Ethernet jack interface, operating at 100 megabits per second. It is ideal for high-speed applications and uses green-colored cables.

What does the red switch on the back of some Profibus connectors control?

The red switch on the back of some Profibus connectors controls the Terminating Resistor. This switch must be set to the 'on' position on the last device in the network and 'off' for every other device to prevent a bus fault.

What is the maximum number of devices that can reside on a single Profibus network?

A single Profibus network can support up to 127 devices, each with a unique address ranging from 1 to 127.

How does the address of a device on a Profibus network get configured?

For some devices, the address is set using software like STEP7 or TIA Portal. For others, the address is configured using DIP switches located on the front of the device.

What is the maximum length of a Profibus cable for different data rates?

While Profibus cables may be up to 1000 meters long, shorter cable lengths are required for higher data rates.

Why are official Profinet cables recommended over standard Ethernet cables?

Official Profinet cables are recommended because they contain robust shielding and are designed to function well in harsh industrial environments, ensuring reliable communication.

What are the three different types of addresses used by Profinet devices?

Profinet devices use an IP address, a MAC address, and a device name. While all Ethernet devices use IP and MAC addresses, the device name is unique to Profinet devices.

What is the typical response time of Profinet, making it suitable for high-speed applications?

Profinet has a response time of less than 1 millisecond, which makes it ideal for high-speed applications.

How does Profinet's use of Ethernet standards affect network expansion?

Because Profinet uses the same physical connection standards as Ethernet, standard Ethernet switches can be used to expand the network, providing greater flexibility.

Why is Profinet becoming the preferred communications protocol for industrial applications?

Profinet is becoming the preferred communications protocol for industrial applications due to its higher speed, greater flexibility, and suitability for high-speed applications.

What is the significance of being familiar with both Profibus and Profinet for a controls engineer?

Being familiar with both Profibus and Profinet is essential for a controls engineer because both protocols are widely used in the industry, and understanding their differences and applications can enhance the engineer's ability to design and maintain industrial control systems.

What is the recommended action for those interested in learning more about PLC programming?

For those interested in learning PLC programming, the script suggests visiting realpars.com for an easy-to-understand format and to take their career to the next level.