USER MANUAL
STM 350 / STM 350U (STEPCODE DE OR HIGER)
TEMPERATURE AND HUMIDITY SENSOR MODULE
© 2019 EnOcean | www.enocean.com
F-710-017, V1.0
STM 350 / STM 350U User Manual | v1.4 | Dec 2019 | Page 4/14
2
GENERAL DESCRIPTION
This user manual specifies STM 350 modules with stepcode DE or later:
See chapter “6.1 Product Label” to find out the module stepcode
User manual for older modules can be downloaded from the product website
For a detailed description of product changes see Product Change Notification (PCN).
2.1
Basic functionality
The extremely power saving RF transmitter
modules STM 350 and STM 350U of EnOcean
is optimized for realization of wireless and
maintenance free temperature and humidity
sensors.
They require no external components and
provides on-board a calibrated temperature
and humidity sensor.
STM 350 and STM 350U wake up at a rate of
approximately once every 100 seconds to read the status of the integrated temperature and
humidity sensor.
If there is a significant change in measured temperature (more than 0.5 K) or humidity (more
than 3% r.h.) versus the last reported values then a radio telegram will be transmitted im-
mediately. In case of no relevant input change, a redundant retransmission signal (heartbeat)
is sent after 15 minutes to announce the current values.
Power is provided to STM 350 and STM 350U by means of a small pre-installed solar cell
which works in conjunction with an integrated energy storage element in order to ensure
operation in periods without ambient light. The available energy within the energy storage
element is continuously monitored and reported regularly.
STM 350 and STM 350U additionally provide the option to connect an external 3 V backup
battery to enable operation with little or no available light.
Key product features
Fully autonomous operation under sufficient lighting with pre-installed solar cell
On-board energy storage and charging circuit with energy level reporting
On-board LRN button
On-board TX indicator LED
Factory calibrated on-board temperature and humidity sensor
Support for high security communication (encrypted and authenticated)
