USER MANUAL V1.12
EnOcean GmbH
Kolpingring 18a
82041 Oberhaching
Germany
Phone +49.89.67 34 689-0
Fax +49.89.67
34
689-50
[email protected]
www.enocean.com
Subject to modifications
PTM 230 User Manual V1.12
June 4, 2008 2:02 PM
Page 7/12
PTM 230
2.3
PTM 230 Radio Telegram
2.3.1
Frequency range and transmission cycle allowed
The EnOcean technology operates the 868.3 MHz radio channel, which is exclusively re-
leased for short-time data transmission in Europe. All transmitters have to stick to a duty
cycle of max. 1% within one hour. Permanent transmitters such as radio earphones are not
allowed. For conventional applications, it must be ensured that the PTM 230 radio module is
not operated more than 15000 times within one hour (one operation: button is pressed and
released). Within this calculation, the extraordinary short telegram length is considered
including three subtelegrams.
2.3.2
Modulation process
As modulation process, EnOcean uses incoherent amplitude modulation (ASK). Digital am-
plitude modulation enables the implementation of very efficient energy-saving transmitters
because only the “1”-bits are transferred. At the same interference signal level, the trans-
mission security of the alternative FSK method is identical to that of the ASK method.
(Reference: Pehl, Digitale und analoge Nachrichtenübertragung, Hüthig 2001)
2.3.3
Transmission timing
The transmission timing of the radio module PTM 230 has been developed to avoid possible
collisions with data packages of other EnOcean transmitters as well as disturbances from
the environment.
With each transmission cycle, three identical subtelegrams are transmitted. The transmis-
sion of a subtelegram lasts approximately 0.7 ms. To optimize data security, each telegram
is repeated twice within about 20 ms, whereas the delay between the second and the third
transmission burst is effected at random.
Figure: PTM 230 radio timing
