DRF1276DM

Revision 2.72

May. 2017

5/13

The SET pin is used in central/node mode to switch the communication ways (

express

communication or breath period communication) of node module. When the EN pin and

the SET pin of the node module are set to logic high or floated, the node module will work in

breath period communication way. It wakes up at the interval of breath period and spend the

short time (wake timer parameter) to monitor the wireless signal so the central module needs

to send a long preamble (>breath period) in order to assure the node module to receive the

data successfully.

Figure 3: Node Module in Breath Period Communication

Wake timer parameter is introduced in version 2.7 in order to provide more flexibility in

power consumption in breath period communication. The wake timer refers to the time length

for the node module to detect the wireless signal when the node module wakes up in the

breath period. The shorter time means less power consumption but it needs the central module

to send data at higher RF data rate. In other words shorter wake timer means less power

consumption but shorter distance because of higher RF data rate.

Figure 4: Wake Timer & Breath Period

In order to reduce the complexity of calculating the wake timer with RF data rate, the node

module will choose the suitable RF_BW and RF_factor parameters automatically according to

the wake timer parameter. Therefore the two parameters RF_BW and RF_factor don’t

function in this mode and users only need to set the wake timer parameter according to the

actual applications.