schlegel csii 400

Control Switches International Inc (Csii), your North American source for Schlegel push buttons, pilot lights, emergency stops, terminal blocks and control products.

Schlegel Wireless Pushbuttons



Battery-Free Wireless Pushbutton Modules for Building Technologies and Industrial Automation

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When planning new industrial buildings and manufacturing plants, intelligent automation solutions are becoming more popular, often using several decentralized control units. However, the wiring of the necessary control elements is quite quickly becoming expensive and inflexible.

Wireless pushbuttons, which do not require any cable, are the solution for this problem. They need no wiring at all and allow very flexible handling and arrangement of the switches and pushbuttons.

Conventional wireless pushbuttons, however, do have two disadvantages: They use batteries for the power supply, on the one hand, which must be changed regularly. On the other hand, the signal transmission takes relatively long (approx. 50 to 70 msec.), which may result in an overlapping of two switching operations so that one of the two signals gets lost.

One way out of this dilemma offers the innovative wireless transmission technology from EnOcean. This technology provides the required energy from the processing and ambient energy. This disposable energy is generated as kinetic energy e.g. during switching operations or vibrations, or even as thermal energy (e.g. by light irradiations or temperature differences). This procedure allows to operate the control units without cable connection and even without batteries, thus, making the units wireless, self-powered and low-maintenance.

The new wireless transmitter modules use this technology for the battery-free transmission of a pushbutton signal. In this case the required energy is produced by the switching operation itself, thus, making it independent from ambient conditions.

Transmission of the radio signal takes place on the licence-free SRD band (Short Range Devices) at 868 MHz with a transmission power of 10mW. Three very short telegrams are sent within 25 ms, including an individual 32-bit ID, the polarity of the supply voltage and the actual playload (one to two input signals). This multiple emitting guarantees utmost transmission security.

The EnOcean wireless standard at a glance :

High Reliability
  • License-free 868 MHz frequency band with 1% duty cycle

  • Multiple telegram emitting with checksum

  • Ultra-short telegrams (approx. 1ms) reduce collision risk to a minimum

  • Broad reach: 30m in buildings & 300m in a free field

  • Repeater available for range extension

  • Unidirectional and bidirectional communication

Low Energy Requirement

  • High data transmission rate of 125 kbit/s

  • Small data overhead

  • ASK modulation


  • Wireless protocol defined and integrated in modules

  • Sensor profiles specified and implemented by users

  • Unique transmission ID (32 bits)

  • Coexistence with other wireless sytems

  • No interference with DECT, WLAN, PMR systems etc.

  • System design verified in industrial environment