SENA ProBee-ZE20S - Manual (Page 33)

33 ProBee-ZE20S User Guide Rev.1.10
4 Data Transmission
The ZE20S supports three different types of data transmissions: unicast, multicast and broadcast. Unicast
is to transmit data to a specific ZigBee device. Multicast is to transmit data to a group of ZigBee devices
that are assigned a specific group ID. Broadcast is to transmit data to all ZigBee devices (or specific type
of ZigBee nodes if specified) in the network.
ZE20S has such operation modes as command mode and data mode. Data can be transmitted at each
operation mode as below:
 Command mode: Because this mode is for entering commands to set and manage a ZE20S, as
many data as allowed are transmitted at a time by using AT command.
 Data mode: Because this mode is for transmitting data, it is possible to send data consecutively.
“+++” changes the operation mode from the data mode to command mode.
4.1 Command Mode
4.1.1 Unicast
Unicast transmissions are sent from a source device to a destination device. The destination device can
be any ZigBee device in the ZigBee network. To specify the destination device, the ZigBee address of the
destination device should be known.
There are two different ZigBee addresses assigned to each ZigBee device. The 64-bit address is a
unique device address assigned during manufacturing. The 64-bit address is also called IEEE address or
extended address. The 16-bit address is assigned to the device when it joins a ZigBee network. The
ZE20S can send unicast messages based on either 16-bit address or 64-bit address. The AT command
for the unicast transmissions is as below:
AT+UNICAST=<node_id>,<MSG><CR> or AT+UC=<node_id>,<MSG><CR>
, where <node_id> = 16-bit or 64-bit address, <MSG> = data to transmit
The maximum payload of the message is 90 bytes (or 72 bytes under security enabled). If the message
length exceeds the maximum payload, the message cannot transmit and the error message will be
presented. The AT command to get the maximum payload is as below:
AT+MAXPAYLOAD?<CR> or AT+MP?<CR>
After unicast transmission timeout, the source device present an error message. Unicast transmission
timeout can be set using the AT commands below. Please refer to the 9 S-Registers for more details.
ATS32=n, where n is the transmission retries.
ATS33=n, where n is the transmission timeout.