The Beckhoff BK3120 PROFIBUS Economy plus Bus Coupler links PROFIBUS DP networks to Beckhoff Bus Terminals, delivering reliable fieldbus communication for modular I/O stations in control cabinets. Built for OEMs, system integrators and maintenance teams, it combines a compact footprint with robust performance for machine and process automation.

With automatic baud rate detection up to 12 Mbaud, the BK3120 handles up to 128 bytes of input and 128 bytes of output process data for fast, deterministic exchange. A shielded D-sub 9-pin interface and 500 V electrical isolation between power contacts, supply and fieldbus bolster noise immunity and system resilience. The coupler operates from 24 V DC (-15%/+20%), supports up to 64 Bus Terminals (expandable to 255 via K-bus extension), mounts on a 35 mm DIN rail, and is suited to IP20 cabinet environments with EMC compliance to EN 61000-6-2/-6-4 and approvals including CE, UL, ATEX and IECEx.

Whether modernizing existing PROFIBUS DP installations or designing new panels, the BK3120 streamlines commissioning and keeps your I/O architecture scalable, and it is backed by a 1-year warranty to provide added assurance throughout the product lifecycle.

• Brand: Beckhoff
• Model: BK3120
• Fieldbus: PROFIBUS DP
• Data rate: Automatic detection up to 12 Mbaud
• Bus interface: D-sub 9-pin (shielded)
• Supply voltage: 24 V DC (-15%/+20%)
• Max process data: 128 bytes input / 128 bytes output
• Bus Terminals supported: up to 64 (255 with K-bus extension)