View source for Set uplinkdwell time

=Introduction=
This chapter introduces how users can change the uplinkdwell time.

=Default uplinkdwelltime=
Take AS923 frequency band as an example. We can see the spread spectrum factor corresponding to the data rate.
[[File:vbn.png|600px|none|thumb|]]

The device default uplinkdwelltime=1, there are SF7, SF8, SF9 and SF10.

If users want to ues SF11 and SF12, they need to set uplinkdwelltime=0.

Users can use AT commands to set uplinkdwell time.

[[File:uplinkdwelltime1.png|600px|none|thumb|]]
[[File:uplinkdwelltime2.png|600px|none|thumb|]]

=Use AT command to set uplinkdwell time=
Since Dragino LoRaWAN Stack DR_LWS_005, user is able to set the uplink Dwelltime in AS923 and AU915 manual or use a application side downlink command to set it. 

* Use AT command: AT+DWELLT=0, set to Uplink Dwelltime=0.
* Use AT command: AT+DWELLT=1, set to Uplink Dwelltime=1.

Or via application downlink command:
* Downlink Payload: 0x2500, Set AT+DWELLT=0 to uplink.
* Downlink Payload: 0x2501, Set AT+DWELLT=1 to uplink.