====== Send data to end-devices ======

Data can be sent to end-devices. It can be achieved using the web interface from the ''Fleet => Send data'' menu (but also from other interfaces).

{{.:..:send_data.png?600|Data can be sent manually or through a CSV file}}

The web interface only displays the last message sent. The web interface displays all the queued messages.\\

__List of available status:__
  * Pending
  * Queued
  * Sent
  * Failed
  * Succeed
  * Try 1, 2, 3, 4, 5 

{{.:..:..:webui:tx_data_list.png?800|Tx data list}}

===== Sending data from a CSV file =====

LoRa frames can be sent to end-devices from a CSV file, and all send frames can be downloaded from the web interface.

==== File Format ====

Templates can be downloaded from the [[.:..:..:releases:2.1:templates|templates]] page.

__Input fields description:__
  * ''end_device_id'': Device EUI or Device Address (depends on activation procedure)
  * ''port'': Port used (in LoRaWAN protocol)
  * ''acknowledge'': true or false
  * ''try_number'': Number of retry before abort
  * ''payload'': Payload in base 64 format

==== Example ====

<file csv xxxxxxxx_tx_data.csv>
18B20000000BAA,2,true,3,dGVzdA==
18B20000000BAA,5,false,3,dGVzdA==
18B20000000BAA,2,false,2,dGVzdA==
</file>

===== Class A communication =====

"Following each uplink transmission the end-device opens two short receive windows. The receive window start times are defined using the end of the transmission as a reference."

"If the network intends to transmit a downlink to an end-device, it will always initiate the transmission precisely at the beginning of one of those two receive windows."

{{.:..:..:images:lora_class_a_transmission.png?450nolink|LoRa class A transmission}}

//Extract from the LoRaWan Specification ([[https://www.lora-alliance.org/ |LoRa-alliance]])//

===== Class C communication =====

"Class C devices implement the same two receive windows as Class A devices, but they do not close the RX2 window until they need to send again. Therefore they may receive a downlink in the RX2 window at nearly any time, including downlinks sent for the purpose of MAC command or ACK transmission. A short listening window on RX2 frequency and data rate is also opened between the end of the transmission and the beginning of the RX1 receive window." 

{{.:..:..:images:lora_class_c_transmission.png?600nolink|LoRa class B transmission}}

//Extract from the LoRaWan Specification ([[https://www.lora-alliance.org/ |LoRa-alliance]])//