USER MANUAL
STM 550X / EMSIX
–
ENOCEAN MULTI-SENSOR
© 2020 EnOcean | www.enocean.com F-710-017, V1.0
STM 550x / EMSIx User Manual | v1.0 | February 2020 | Page 9/79
2
Functional overview
2.1
Product description
The energy-harvesting multi-sensor STM 550x using the STM 550x multisensor module pro-
vides wireless sensing functionality without batteries. Power is provided by a connected solar
cell. STM 550x transmits sensor data using the EnOcean radio standard.
STM 550x operates fully self-powered (no batteries required) when sufficient available am-
bient light (200 Lux for 6 hours per day) is available. In this configuration it is fully mainte-
nance-free.
For cases where sufficient ambient light is not available there is the option to mount a CR1632
backup battery.
Radio telegrams transmitted by STM 550x can be authenticated and encrypted using AES-
128 security based on a device-unique private key and a sequence counter in accordance to
the EnOcean Alliance Security Specification. This ensures integrity, confidentiality and au-
thenticity of the transmitted telegrams and prevents telegram replay (retransmission of pre-
viously transmitted telegrams).
2.2
Product interface
The STM 550x product interface consists of the following elements:
◼
LRN button and LED as described in chapter 2.2.1
◼
Solar cell harvesting energy from ambient light as described in chapter 2.2.2
◼
Ambient light sensor (co-located with the LED) as described in chapter 3.
◼
Magnet contact sensor as described in chapter 3.6
◼
Ventilation slots to ensure airflow to the temperature and humidity sensor
◼
Backup battery slot for a CR1632 battery as described in chapter 2.2.3
◼
Backup battery ejector slot (on the back side) as described in chapter 2.2.3
◼
Product label (on the back side) as described in chapter 2.2.4
Figure 2 below shows the external interfaces on the front side of the STM 550x module.
Figure 2
–
STM 500x external interfaces