USER MANUAL V1.0
© 2016 EnOcean | www.enocean.com
F-710-017, V1.0
PTM 535Z User Manual | v1.0 | March 2016 | Page 20/38
PTM 535Z – 2.4 GHZ PUSHBUTTON TRANSMITTER MODULE
3
IEEE 802.15.4 Frame Structure
PTM 535Z transmits radio telegrams in the 2.4 GHz band according to IEEE 802.15.4 frame
structure. For detailed information about the IEEE 802.15.4 standard, please refer to the
applicable specifications.
The following information about the IEEE 802.15.4 frame structure is given for reference
only. Note that the data format used is little endian. This means that for multi-byte struc-
tures (such as 2 byte, 4 byte or 8 byte fields) the least significant byte (LSB) is transmitted
first. The IEEE 802.15.4 frame structure used by PTM 535Z consists of the following four
main parts:
PHY Header
The PHY header indicates to the receiver the start of a transmission and provides infor-
mation about the length of the transmission.
It contains the following fields:
-
Preamble
Pre-defined sequence (4 byte, value 0x00000000) used to adjust the receiver
to the transmission of the sender
-
Start of frame
Pre-defined symbol (1 byte, value 0xA7) identifying the start of the actual
data frame
-
Length
1 byte indicating the combined length of all following fields
MAC Header
The MAC header provides detailed information about the frame.
It contains the following fields:
-
Frame control field
2 bytes to identify frame type, protocol version, addressing and security
mode
-
Sequence number
1 byte sequential number to identify the order of transmitted frames
-
Address
PAN ID and address of source (if present) and destination of the telegram
PTM 535Z does not use source address and source PAN ID
MAC Payload
The MAC Payload field contains telegram control, device ID, telegram data and telegram
security (if present) fields.
The MAC Payload field structure depends on telegram type (data or commissioning) and
security mode (secure or non-secure transmission).
MAC Trailer
The MAC Trailer contains the Frame Check Sum (FCS) field used to verify the integrity of
the telegram data.