USER MANUAL
EMDCB
–
BLUETOOTH LOW ENERGY MOTION AND ILLUMINATION SENSOR
© 2019 EnOcean | www.enocean.com
EMDCB User Manual | v1.3 | August 2019 | Page 26/67
4.6
Payload
The payload of EnOcean BLE sensor data telegrams can in general be up to 31 bytes long
(depending on the size of the sensor data) and consists of the following fields:
◼
Length (1 byte)
The Length field specifies the combined length of the following fields and depends on
the size of the Sensor Status field. The minimum length is 13 byte and the maxi-
mum length is 31 byte
◼
Type (1 byte)
The Type field identifies the data type used for this telegram. For STM 500B data
telegrams, this field is always set to
0xFF
to designate manufacturer-specific data
field
◼
Manufacturer ID (2 byte)
The Manufacturer ID field is used to identify the manufacturer of BLE devices based
on assigned numbers. EnOcean has been assigned
0x03DA
as manufacturer ID code.
◼
Sequence Counter (4 byte)
The Sequence Counter is a continuously incrementing counter used for security
processing. It is initialized to
0
at the time of production and incremented for each
telegram (data telegram or commissioning telegram) sent.
◼
Sensor Data (variable size)
The Sensor Data field reports the measured values of the sensors. The encoding of
this field is described in chapter 4.6.1.
◼
Security Signature (4 byte)
The Security Signature is used to authenticate EnOcean BLE sensor data telegrams,
see chapter 5.
Figure 17 below illustrates the general telegram payload structure.
Figure 17
–
Telegram payload structure
