Cables in PROFINET Installations
A PROFINET network is based on standard IEEE 802.3 Ethernet. You can utilize standard Ethernet cables (fiber optics or copper cables) in a PROFINET network.
The most commonly used PROFINET copper cable is the 4-wire shielded, green-colored cable, which supports 100 Mbps Fast Ethernet at a distance of 100 meters. You can achieve Full-Duplex transmission: meaning data can be transmitted in both directions through one cable simultaneously. Also, 8-core copper cables are available for 1 Gbps transmission rates. To go further distances than the 100-meter limit, you have to install a node, like, for example, a switch, every 100 m.
A common question about copper cables in PROFINET applications is if you can implement Cat 5, 5e, Cat 6, 6a, or Cat 7 cables in PROFINET networks?
The short answer is “Yes,” you can implement these cables. However, the categories only specify the performance of the cable like achievable frequency, speed, crosstalk, and signal-to-noise ratio. You must also check the specifications of each cable. Some older Cat 5 cables, for example, are unsuitable as they are only capable of 10 Mbps speeds, which is below the required 100 Mbps for PROFINET.
That said, Cat 5e is the most common, as it can fulfill the 100 Mbps transmission speeds.
Cat 6, 6a, and Cat 7 cables can provide transmission speeds of up to 10 Gbps. Such high rates might seem unnecessary based on current hardware transmission speed capabilities, but some users choose them to future-proof their network.
PROFINET networks can employ all of these, but the Categories alone don’t address their use in industrial environments. The cabling you choose should also, therefore, meet the PROFINET specification.
Learn more about cabling and assembly in PROFINET projects by reviewing this comprehensive guideline (free PDF download):