USER MANUAL
ETHSA / ETHSU
ENOCEAN TEMPERATURE AND HUMIDITY SENSOR
© 2022 EnOcean | www.enocean.com
F-710-017, V1.0
ETHSx User Manual | April 2022 | Page 12/27
3
FUNCTIONAL DESCRIPTION
3.1
Block Diagram
Figure: Hardware block diagram (simplified)
3.2
Measurement and Transmission Timing
ETHSx wakes up approximately once every 100 seconds to measure temperature and hu-
midity. The measured values are then compared against the last reported (transmitted) val-
ues. If there is a significant change then the measured values are transmitted immediately.
Significant change is defined as follows:
◼
Temperature: The measured temperature deviates from the last reported tempera-
ture by more than 0.5 K
◼
Humidity: The measured humidity deviates from the last reported humidity by more
than 3% r.h.
In absence of a significant change, a heartbeat telegram reporting the currently measured
values is transmitted for every 7 to 14 measurements (affected at random). In addition,
ETHSx measures and reports the energy level of its internal energy storage element approx-
imately every 100 measurements. With each default transmission cycle, 3 identical sub-tel-
egrams are transmitted within 40ms. Transmission of a sub-telegram lasts approximately
1.2ms. The delay between the three transmission bursts is affected at random. This setup of
the transmission timing allows avoiding possible collisions with data packages of other
EnOcean transmitters as well as disturbances from the environment.