KNX IO 512 secure

 KNX IO 512 secure

KNX IO 512 secure – Switch actuator 12-fold

The KNX switching actuator KNX IO 512 secure offers 12 bistable relay outputs that are optimised primarily for the requirements of LED lights. However, other loads can also be switched.

The actuator offers comprehensive functions for universal outputs including scenes, switch-on and switch-off delay, staircase lighting switching and the control of heating valves (PWM for thermal actuators). In addition, the device offers independent logic and time functions.

The device supports KNX Data Security.

KNX Block IO: Reliable and safe

The KNX IO 512 secure – 12-fold switching actuator is based on the new KNX Block IO platform from Weinzierl. It offers a high channel density and consistently focusses on reliability and security. Support for KNX security is therefore a matter of course.

Central power supply with mains monitoring

The new platform is characterised by a central feed for all channels. This enables quick and clear wiring in the control cabinet and monitoring of the mains voltage. A mains failure is indicated by an LED on the device and can also be signalled with a group telegram on the bus.

16 A input current, 12x 16 A output current

What sounds like a contradiction is actually a balanced dimensioning, especially for LED lighting. LED lights are characterised by their relatively low power consumption. The power consumption of typical residential luminaires is usually well below 100 W. At the same time, LED luminaires have a very high input current due to their capacitive input characteristics. This is why the individual switching channels, including the relays, are dimensioned for a switching capacity of 16 A.

Switching at zero crossing

Very high inrush currents can occur with capacitive loads such as fluorescent lamps, but especially with LED lights. These loads, often referred to as C loads, place a heavy load on the contact material of the relay and can significantly shorten the service life of the relay.

To avoid high inrush currents, the KNX IO 512 secure can set the switching time when switching on to the zero crossing of the mains voltage. This not only considerably extends the service life of the relays but also avoids current peaks in the system.

Offset switching

Another function for avoiding current peaks is the offset switching of central commands. If several channels are switched on at the same time, a time offset can be set between the channels.This function is also effective when restoring the power supply after a power failure. The parameters enable load shedding in the event of a power failure and delayed switch-on on recovery. This also prevents possible tripping of the line protection (fuse), which can occur when up to 12 LED lights are switched on at the same time.

Manual operation with multiple selection, even without bus

The devices allow multiple selection for manual operation. This allows several channels to be switched simultaneously. Manual operation is also possible without bus voltage.

Direct switching with the ETS

In addition to manual operation on the device, the new series also enables direct control of the channels from the parameter area of the ETS. This means that all channels can be switched on and off individually or all at the same time. Only the physical address of the device needs to be programmed for this. No parameter settings or group addresses are required. This makes it possible to switch the outputs directly with the ETS – even in remote maintenance.

Screenshot Ets Aktor 512 2024 03 04 002 En

Technical data

Mechanical data

  • Housing: plastic (PC)
  • DIN rail mounted device, width: 6 modules (108 mm)
  • Weigth: approx 350 g

User Interface

  • 4 buttons and 14 LEDs, multicolor
  • KNX programming button with LED


  • Device Model System B
  • Compatible with ETS 5 (or higher)
  • Support of KNX Security


  • Connector for KNX Bus (red / black)
  • Pluggable screw connector (12 poles) for outputs
  • Pluggable screw connector (2 poles) for 230V~


  • Centralised for all channels 230 V~ / 16 A
  • With mains monitoring on KNX


  • 12 channel switching actuator
  • Relay type: 230 V~ / 16 A, bistable
  • Depending on load type (capacitive / inductive) the switching power can be reduced significantly
  • Switching in zero crossing
  • Time-delayed switching with centralised commands