Duty Cycle - HomeMatic HmIP-STH Mounting Instruction And Operating Manual

Troubleshooting
7.3

Duty cycle

The duty cycle is a legally regulated limit of the transmis-
sion time of devices in the 868 MHz range. The aim of
this regulation is to safeguard the operation of all devices
working in the 868 MHz range.
In the 868 MHz frequency range we use, the maximum
transmission time of any device is 1% of an hour (i.e. 36
seconds in an hour). Devices must cease transmission
when they reach the 1% limit until this time restriction
comes to an end. Homematic IP devices are designed and
produced with 100% conformity to this regulation. During
normal operation, the duty cycle is not usually reached.
However, repeated and radio-intensive teach-in pro-
cesses mean that it may be reached in isolated instances
during start-up or initial installation of a system. If the duty
cycle is exceeded, this is indicated by three long flashes
of the device LED, and may manifest itself in the device
temporarily working incorrectly. The device starts working
correctly again after a short period (max. 1 hour).
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