The frequency that the SRD transmitter and receiver modules use, 868.95 MHz, is in a frequency range newly approved for short-term signal transfers. Through low-use by other radio services and the mandatory channel separation, a disturbance-free signal is guaranteed. The modules are useful for transferring serial data, for example, for setting up an alarm system, to turn on signals and for sending alarm signals, measurements and similar from a distance of up to 100 metres. Electromagnetic interference fields, structures and stray radiation from machinery may lessen the range. The modules have general approval and can be used in the EU (with the exception of Greece) without registration or payment of fees. Connection is made over a pin connector with a pin spacing of 2.54 mm.
