Operation
Single frequency mode band mode
XBee 868LP RF Modules User Guide
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Effective Duty Cycle = (number of channels * 100)/3600.
For example, if you enabled two channels you would have an effective duty cycle of 5.6%.
The XBee 868LP RF Module uses a sliding bucket algorithm to calculate usage over the period of 1
hour for each channel. Each bucket accumulates for 6 minutes.
This device has a maximum of 30 AFA channels to choose from, and channels can be excluded by
setting the channel mask (
CM
) to reduce them. Since not all countries allow for all of these channels,
the set may be dramatically smaller for some countries. For a complete list, refer to
.
Single frequency mode band mode
When you set the channel mask to 0x20000000, the device is in a single frequency mode, and the
frequency is 869.85 MHz. In this mode:
n
LBT+AFA mode is disabled.
n
The device assumes no duty cycle requirement (or 100% duty cycle).
n
The
PL
setting must be set to 5 mW to comply with the single frequency mode requirements.
Serial communications
RF Modules interface to a host device through a serial port. Using its serial port, the device
communicates with any of the following:
n
Logic and voltage compatible UART
n
Level translator to any serial device (for example, through an RS-232 or USB interface board)
UART data flow
Devices that have a UART interface connect directly to the pins of the XBee 868LP RF Module as
shown in the following figure. The figure shows system data flow in a UART-interfaced environment.
Low-asserted signals have a horizontal line over the signal name.
Serial data
A device sends data to the XBee 868LP RF Module's UART through pin 4 DIN as an asynchronous serial
signal. When the device is not transmitting data, the signals should idle high.
For serial communication to occur, you must configure the UART of both devices (the microcontroller
and the XBee 868LP RF Module) with compatible settings for the baud rate, parity, start bits, stop bits,
and data bits.
