User's Manual

USER MANUAL PREVIEW

PTM 535BZ – BLUETOOTH AND ZIGBEE GREEN POWER PUSHBUTTON TRANSMITTER

4.4.3 Decommissioning telegram

Transmission of a decommissioning telegram can be selected only via the NFC interface.

The payload of decommissioning telegrams is 12 byte long and shown in Figure 34 below.

Figure 34 – Structure of ZGP decommissioning telegrams

For security reasons, SECURITY_KEY2 will be automatically updated by PTM 535BZ to a new

random value when a decommissioning request is transmitted. This prevents the case of

using the same security key in different networks.

4.4.4 Data telegram authentication

PTM 535BZ implements telegram authentication for transmitted ZGP data telegrams as spec-

ified by the ZGP specification. This ensures that only telegrams from transmitters using a

previously exchanged security key will be accepted by the receiver. Refer to the ZGP speci-

fication [3] for details about ZGP data telegram authentication.

4.5 Channel selection

ZGP uses the IEEE 802.15.4 radio standard [5] for telegram transmissions which defines 16

radio channels (designated as Channel 11 … Channel 26) as described in Chapter 4.1.

The radio channel used for communication is selected when a ZGP network is formed and

usually remains the same throughout the lifetime of the network. The channel selection pro-

cess is designed to ensure that a certain channel quality (low disturbances) is achieved.

Four of the 16 radio channels (Channel 11, Channel 15, Channel 20 and Channel 25) are

designated as Primary Channels and will be tried first in the channel selection process. Most

ZGP networks therefore operate on one of these four primary channels.

Devices within a ZGP network can receive radio telegrams from PTM 535BZ only if PTM 535BZ

uses the same radio channel as the ZGP network. PTM 535BZ therefore has to be configured

to use the right radio channel. This process is called channel selection.

Channel selection can either be executed via the NFC interface or via the LRN button. Both

options are described below.