Beckhoff
PC-Based Control and TwinCAT 3 Building Automation
Beckhoff (Verl, Germany) is a leading industrial automation company — TwinCAT 3 software PLC and EtherCAT real-time I/O are used in advanced building automation projects requiring deterministic control, complex logic, and multi-protocol integration in a single controller. The EL6900 KNX terminal provides native KNX TP bus master capability.
Role in our panels
How we use Beckhoff
CX9020 Embedded PC: ARM-based fanless DIN rail controller running TwinCAT 3 runtime — acts as KNX IP router and logic controller simultaneously. EL6900 EtherCAT terminal: KNX TP bus master module (DIN rail EtherCAT slice) — reads/writes KNX group objects directly from TwinCAT 3 structured text code without a separate gateway. TwinCAT 3 Building Automation (BA) library: ready-made function blocks — FB_KNX_Switch (on/off), FB_KNX_RoomController (PI setpoint control, valve output, fan speed), FB_KNX_DALI (dimming, scene), FB_HVAC_VAV (variable air volume). BACnet/IP: BK9050 coupler or TwinCAT BACnet TC3 library — enables bidirectional connection to Metasys, ECLYPSE, Priva BMS. Modbus TCP: TwinCAT Modbus TCP library polls energy meters, inverters, and HVAC units in parallel. KNX Secure: TwinCAT 3 supports KNX Data Security — group object encryption and device authentication. Use cases: large commercial buildings where PLC-level determinism is needed (guaranteed 10ms scan cycle for HVAC control), multi-protocol consolidation (KNX + BACnet + Modbus in one controller), and complex energy management algorithms.
Beckhoff EL6900 EtherCAT terminal provides native KNX TP bus master — TwinCAT 3 BA library function blocks read/write KNX group objects directly, enabling complex building logic with deterministic 10ms scan cycles.
Used in these project types
Beckhoff products
Key components we install
CX9020 Embedded PC TwinCAT 3
ARM-based fanless DIN rail PLC running TwinCAT 3 runtime for KNX and multi-protocol building automation
EL6900 KNX/EIB terminal
EtherCAT KNX TP bus master module — native KNX group object read/write from TwinCAT 3 structured text
BK9050 BACnet/IP coupler
BACnet/IP communication coupler for integration with Metasys, ECLYPSE, and Priva BMS systems
EK1100 EtherCAT coupler
EtherCAT bus coupler for expanding I/O with digital, analogue, and specialty EtherCAT terminal slices
Beckhoff FAQ
Do I need a separate KNX IP interface with Beckhoff?
No — EL6900 directly accesses the KNX TP bus; TwinCAT 3 communicates via EtherCAT to EL6900 without a separate gateway.
Can TwinCAT 3 connect to both KNX and BACnet simultaneously?
Yes — run EL6900 for KNX TP bus master and BK9050 or TC3 BACnet library for BACnet/IP simultaneously in a single TwinCAT 3 project.
What minimum PLC performance is needed for a KNX building project?
CX9020 (ARM Cortex-A9) is sufficient for 200 KNX objects + Modbus + BACnet polling. For 1000+ objects use CX5140 (Intel Atom) for higher throughput.
Need a panel with Beckhoff components?
We select, procure, assemble and certify. Free initial consultation.
Request consultation →