User's Manual

USER MANUAL PREVIEW
PTM 535BZ – BLUETOOTH AND ZIGBEE GREEN POWER PUSHBUTTON TRANSMITTER
© 2022 EnOcean | www.enocean.com F-710-017, V1.0 PTM 535BZ User Manual | v1.2 | July 2021 | Page 21/121
3.4 Telegram payload
As described before, PTM 535BZ can transmit two types of BLE telegrams which use different
telegram payloads:
 Data telegrams
The payload of data telegrams contains the input status together with the current
sequence counter value and the resulting authentication signature
 Commissioning telegrams
The payload of commissioning telegrams contains the private security key as well as
the current value of the sequence counter and the device address
The payload structure of both telegram types is described in the following chapters.
3.4.1 Data telegram payload
The payload of data telegrams is 13 byte long and consists of the following fields:
 Length (1 byte)
The Length field specifies the combined length of the following fields. The content of
the field is 0x0C to identify 12 byte of payload that follow
 Type (1 byte)
The Type field identifies the data type used for this telegram. For PTM 535BZ data
telegrams, this field is always set to 0xFF to designate manufacturer-specific data
 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.
The Manufacturer ID can be changed via NFC as described in Chapter 5.6.5.
 Sequence Counter (4 byte)
The Sequence Counter is a continuously incrementing counter used for security pro-
cessing. It is initialized to 0 at the time of production and incremented for each tele-
gram (data telegram or commissioning telegram) sent.
 Input Status (1 byte)
The Input Status field reports the button action. The encoding of this field is described
in Chapter 3.4.1.1.
 Security Signature (4 byte)
The Security Signature is used to authenticate PTM 535BZ radio telegrams as de-
scribed in Chapter 3.4.2
Figure 14 below illustrates the data telegram payload structure.
LEN
0x0C
TYPE
0xFF
MANUFACTURER_ID
0x03DA (EnOcean)
SEQUENCE_COUNTER
Variable (4 byte sequence counter)
INPUT_STATUS
Variable (1 byte status)
AUTHENTICATION_SIGNATURE
Variable (4 byte telegram signature)
Figure 14 – Data telegram payload structure