• This is a sample project demonstrating how to use various building automation fieldbus protocols with Beckhoff TwinCAT 3.
• Minimum TwinCAT version: 3.1.4024.74
• Each fieldbus protocol lives in its own PLC project within a single TwinCAT solution. They can be enabled or disabled independently.
• The DIOC (Fixsus) sub-project requires the third-party DiocLibrary from Upzio, which must be installed separately.
• BACnet Rev12 contains only an empty MAIN program and serves as a placeholder configuration.
• Hardware terminals (KL6301, KL6581, KL6781, KL6821, KL6831, EL6821, EL6851) must be present and configured in the I/O tree for the corresponding sub-project to function.

Demonstrates BACnet/IP communication using the TwinCAT 3 BACnet Rev14 library. Creates a hierarchical BACnet object tree with buildings (Office, Production Plant, Warehouse), levels, and rooms, each containing analog input (AI) objects for temperature readings and analog value (AV) objects for setpoints.

• Uses FB_BACnet_Adapter for adapter state, FB_BACnet_View for hierarchy nodes, FB_BACnet_AI / FB_BACnet_AV for data points
• Requires a BACnet I/O Device configured in the TwinCAT project

Controls a TP10 DIOC touch panel (Upzio/Fixsus) with LEDs, buttons, and environmental sensors (temperature, humidity, CO2, air quality).

• Uses FB_TP10 from the third-party DiocLibrary
• Requires {attribute 'TcCallAfterOutputUpdate'} and a 12 ms task cycle

DALI lighting control via the EL6821 EtherCAT terminal using the TwinCAT 3 DALI library.

• Uses FB_EL6821Communication for terminal communication and FB_DALI102DirectArcPowerControl for dimming
• Sets DALI address 10 to power level 127 (mid-range) as an example

DMX512 master and slave communication via the EL6851 terminal for stage/architectural lighting.

• Master (P_DMX_Master): sends up to 512 channels of DMX data using FB_EL6851CommunicationEx
• Slave (P_DMX_Slave): receives DMX channel data (default 64 channels, configurable)

KNX/EIB communication via the KL6301 Bus Terminal for home and building automation.

• Uses KL6301 FB with physical address configuration and group address filtering (up to 8 filters)
• Demonstrates bit-level send/receive with FB_EIB_BIT_SEND / FB_EIB_BIT_REC and multiple trigger modes (manual, polling, on-change)
• Includes helper function F_EIB_GroupAddress to construct group addresses from main/sub/number

EnOcean wireless sensor/switch communication via the KL6581 Bus Terminal.

• Uses FB_KL6581 for terminal communication and FB_Rec_RPS_Switch to decode 4-pushbutton rocker switch telegrams
• Supports up to 64 KL6581 terminals

M-Bus (Meter-Bus) communication via the KL6781 Bus Terminal for reading energy meters and utility meters.

• Standard (P_MBus): uses FB_MBUS_EMU_32x7 to read operating hours, energy, power, and error status from a meter
• Fast (P_MBus_Fast): uses FB_MBUSKL6781 with global I/O variables for higher-speed polling (2 ms task)

DALI lighting control via the KL6821 Bus Terminal using the older TwinCAT 2 DALI library.

• Uses FB_KL6821Config for digital input event configuration (watchdog, DI1/DI2 edges) and FB_DALIV2DirectArcPowerControl for dimming
• Demonstrates configuration of the KL6821 command buffer

DALI lighting control via the KL6821 Bus Terminal using the TwinCAT 3 DALI library.

• Uses FB_KL6821Communication with embedded initialization link and FB_DALI102DirectArcPowerControl
• Simplified setup compared to the Tc2 variant

SMI (Standard Motor Interface / Somfy) control for motorized blinds and screens via the KL6831 Bus Terminal.

• Uses FB_KL6831KL6841Config for digital input assignment, FB_SMIDown / FB_SMIUp for motor control, and FB_SMIDiagAll for diagnostics
• Supports priority-based Up/Down commands on DI1/DI2

Modbus RTU serial communication in both master and slave roles.

• Master (P_ModbusRTU_Master): sequential state machine reading input/holding registers and writing to slave devices via ModbusRtuMasterV2_PcCOM (also supports KL6x5B/KL6x22B variants)
• Slave (P_ModbusRTU_Slave): exposes input registers (256 words), output registers (256 words), and memory area (2048 words) at device address 17

Modbus TCP/IP master communication over Ethernet.

• Uses FB_MBReadInputs and FB_MBWriteRegs to communicate with a Modbus TCP slave at a configurable IP address and port
• Demonstrates reading input registers and writing holding registers

PROGRAM MAIN
VAR
END_VAR

P_BacnetRev14();

PROGRAM P_ModbusRTU_Master
VAR
    fbModbus    : ModbusRtuMasterV2_PcCOM;
    Rcv         : ARRAY[0..100] OF WORD;
    Step        : INT := 0;
END_VAR

CASE Step OF
    0:  // Read 6 input registers from device 10, starting at register 0
        fbModbus.UnitID         := 10;
        fbModbus.Quantity       := 6;
        fbModbus.MBAddr         := 0;
        fbModbus.cbLength       := SIZEOF(Rcv);
        fbModbus.pMemoryAddr    := ADR(Rcv);
        fbModbus.ReadInputRegs  := TRUE;
        Step := 1;
    1:  // Wait for completion
        fbModbus.ReadInputRegs  := FALSE;
        IF NOT fbModbus.BUSY THEN
            Step := 0;
        END_IF
END_CASE

fbModbus();

Adapt each example by replacing device addresses, register maps, DALI short addresses, or group addresses with values matching your field installation.

• The DIOC sub-project requires the TcCallAfterOutputUpdate attribute on MAIN and a 12 ms task cycle for correct communication timing with the TP10 panel.
• The KL6301 EIB/KNX project uses a GVL_IO with 24-byte input/output arrays mapped to the terminal process data; the KL6781 M-Bus fast variant similarly uses a GVL_IO for shared I/O structures.
• Modbus RTU master code includes commented-out variants for KL6x5B and KL6x22B Bus Terminals — uncomment the appropriate FB type for your hardware.
• The BACnet Rev14 sub-project creates all BACnet objects dynamically at runtime via PLC code; the BACnet I/O Device must be configured in the TwinCAT I/O tree first.
• For M-Bus fast polling, the task runs at 2 ms (priority 9) to ensure timely serial communication with the KL6781 terminal.

Required libraries

Supported platforms: x64 (64-bit)

Minimum TwinCAT version: 3.1.4024.74

License: BSD Zero Clause