User's Manual

USER MANUAL V1.05

STM 320 / STM 320C / STM 320U

3 FUNCTIONAL DESCRIPTION

3.1 Block diagram

A change of the reed contact status or pushing the LRN button will wake the transmitter

unit to send a radio telegram immediately (reed contact position, LRN push button status,

unique 32-bit sensor ID, checksum). In addition a redundant retransmission signal is sent

to announce the contact status even in case of no input signal changes. This signal trans-

mitted every 20-30 min, affected at random. The transmit indicator LED flashes briefly at

every radio transmission.

Between the wake-up phases, the device is in sleep mode for minimum power consump-

tion.

3.2 Radio telegram

STM 320 transmits a radio telegram according to EnOcean Equipment Profile

EEP D5-00-01 as defined in the EnOcean Equipment Profiles 2.1 specification.

http://www.enocean-alliance.org/fileadmin/redaktion/enocean_alliance/pdf/EnOcean_Equipment_Profiles_EEP2.1.pdf

3.3 Transmit timing

The setup of the transmission timing allows avoiding possible collisions with data packages

of other EnOcean transmitters as well as disturbances from the environment. With each

transmission cycle, 3 identical subtelegrams are transmitted within 40 ms. The transmis-

sion of a subtelegram lasts approximately 0.9 ms. The delay between the three transmis-

sion bursts is affected at random.

Helical antenna

BALUN

Spontaneous

wake-up

Power management

Micro

Controller

RF Transmitter

868.3 MHz (STM 320)

315.0 MHz (STM 320C)

902.875 MHz (STM 320U)

DOLPHIN

EO3000I

16MHz Oscillator

Energy

Storage

Solar Cell

LRN button

Transmit

Indicator

Reed

contact