Description
Directly integrating Standard Motor Interface drives into the modular K-bus terminal system, the Beckhoff KL6831 enables high-precision coordination of up to 16 SMI LoVo actuators. This single-channel terminal serves as a dedicated communication gateway, facilitating bilateral data transfer between the control processor and intelligent roller shutter or solar protection drives. Operating on the low-voltage SMI LoVo physical layer, the Beckhoff KL6831 minimizes system wiring overhead and bridges the field level directly to the controller process image using 24-byte input and output maps. Additionally, the integration of local hardware inputs permits commissioning sequences prior to network software configuration.
Features
- Supports connection of up to 16 SMI LoVo (Low Voltage 24 V DC) actuator slaves.
- Features two integrated 24 V DC digital inputs on the terminal body for simplified local commissioning and manual testing.
- Provides galvanic isolation up to 1500 V DC between the SMI bus and the internal K-bus.
- Implements continuous diagnostic monitoring of motor state feedback via the TwinCAT PLC SMI library.
- Supports flexible line topologies extending up to a maximum aggregate cable distance of 200 meters.
Applications
- Automated solar shading, louver control, and blind adjustment in high-exposure commercial facades.
- Industrial cleanroom shading systems utilizing 24 V DC Low Voltage motors.
- Integration of automated window and ventilation actuators in building management networks.
Technical Specifications
| Parameter |
Specification Value |
| Manufacturer |
Beckhoff Automation |
| Model Number |
KL6831 |
| Product Type |
SMI Bus Terminal (LoVo) |
| Number of Channels |
1 |
| Supported SMI Slaves |
Maximum 16 |
| Data Transfer Rate |
2400 baud |
| SMI Bus Topology |
Line topology |
| Maximum Cable Length |
200 m |
| Process Image Width |
24 Byte input / 24 Byte output |
| Nominal Input Voltage |
24 V DC (-15% / +20%) |
| Current Consumption (K-bus) |
Typically 55 mA |
| Electrical Isolation |
500 V (K-bus to SMI-bus) |
| Insulation Voltage |
1500 V DC (SMI to K-bus); 1500 V AC (SMI to Power Contacts) |
| Protection Rating |
IP20 |
| Operating Temperature |
0 to +55 degC |
| Storage Temperature |
-25 to +85 degC |
| Relative Humidity |
95% non-condensing |
| Country of Origin |
Germany |
| Shipping Weight (Calculated) |
0.15 kg |
| Package Dimensions (Calculated) |
120 mm x 80 mm x 25 mm |
Connections and Interfaces
| Terminal Point |
Signal Assignment |
Description |
| 1 |
SMI I+ |
SMI Bus positive connection |
| 2 |
SMI I- |
SMI Bus negative connection |
| 3 |
Input 1 |
Digital input 1 (24 V DC) for local actuator commissioning |
| 4 |
Input 2 |
Digital input 2 (24 V DC) for local actuator commissioning |
| 5 |
24 V DC |
SMI external supply input (positive contact) |
| 6 |
0 V |
SMI external supply input (ground contact) |
Empirical Engineering Insights
Alternative Models & Compatibility
The KL6831 is specifically built for 24 V DC SMI LoVo standard actuators. If your installation utilizes standard line-voltage (230 V AC) SMI actuators, you must deploy the alternative KL6832 module to prevent irreversible hardware damage. Both terminals share the same TwinCAT PLC library blocks, allowing straightforward porting of PLC application code between 24 V and 230 V architectures.
Application Pitfalls & Engineering Notes
While the theoretical SMI bus limit is 200 meters, signal integrity degrades in high-EMI environments when run parallel to medium-voltage power lines. Always route the SMI communication pairs in shielded, twisted-pair cables. To avoid voltage dropouts across LoVo lines, recalculate the supply wire cross-section based on the cumulative peak inrush currents of all 16 connected drives during simultaneous startup cycles.
Commissioning & Wiring Tips
The integrated digital inputs 1 and 2 allow commissioning personnel to drive the SMI actuators up and down directly at the terminal strip before configuring the TwinCAT software or mapping the bus coupler. This minimizes on-site commissioning timelines by isolating physical wiring faults from PLC code issues. Ensure the 24 V DC power contacts are correctly linked via the adjacent terminal power feed-in points.
Installation Guidelines
CRITICAL WARNING: De-energize all primary field power supplies and K-bus coupler modules before inserting or removing the terminal block. Hot-plugging any I/O terminals into the active backplane can cause transient voltage spikes, resulting in logic corruption or permanently damaging the K-bus transceivers.
1
Mount the terminal by sliding it onto a standard 35 mm DIN rail (EN 60715) until the lock release latch clicks firmly.
2
Ensure physical side-by-side locking connections with adjacent terminals to maintain internal K-bus contact integrity.
3
Strip field wires to the specified length and insert them into the spring-clamp terminals using a suitable flathead tool.
4
Apply 24 V DC external supply voltage to power contacts to energize the SMI LoVo bus system.