Texas Instruments CC900DB, Руководство пользователя, Страница: 5 / 20

SWRU064
5
The modules will enter sleep mode after being left without operation for about one
minute. The CC900 and the micro-controller are then in power-down mode, ensuring
minimum power consumption.
The timing diagram below illustrates a packet transmission sequence when the
transmission is initiated from device number 2.
2.3 System parameters
The system parameters used to generate the configuration data for the CC900DB is
shown below. This is a printout from the SmartRF
®
Studio software.
System parameters:
X-tal frequency: 12.000000 MHz
X-tal accuracy: +/- 25 ppm
RF frequency: 868.300 MHz
IF stage: 200 kHz
Frequency separation: 40 kHz
Data rate: 1.2 kbps
Power amplifier class: Class AB
RF output power: -10 dBm
Mode: RX
Receiver mode: Optimum sensitivity
LOCK indicator: Continuous
VCO gain: 100
2.4 Configuration register data
Based on the system parameters referred above, the following configuration data is
generated. This is a printout from the SmartRF
®
Studio software.
DEVICE 1
DEVICE 2
Receiver polling
Devices are active for two
minutes until time-out
Initial
trans-
mission Message
shown on
receiver LED
LED (ACK)
RX LED TX ACK
TX RX
Ack.
trans-
mission Acknowledge
shown on
receiver LED
Sleep
mode