I created a simple gateway that can handle sending messages to nodes (download).
Right after the gateway has sent a rxpk message to the router, the router sends back a txpk message.
sent: {"rxpk:{“rssi”:-71,“stat”:1,“modu”:“LORA”,“rfch”:0,“tmst”:162072576,“datr”:“SF9BW125”,“lsnr”:-52.25,“time”:“2016-06-30T23:22:51.866064Z”,“codr”:“4/5”,“data”:“QHBhYUqABgABrMV/bv6WmQHDDT9bH4AjAzE=”,“freq”:868.099976,“chan”:0,“size”:26}]}
received: {“txpk”:{“rfch”:0,“modu”:“LORA”,“freq”:869.525,“data”:“YHBhYUoAAgABj9/clY414A”,“ipol”:true,“powe”:27,“codr”:“4/5”,“datr”:“SF9BW125”,“tmst”:164072576,“size”:16}}
I would expect the network to send a txpk for the first RX_SLOT first. This package should use the same frequency and data rate as the message received. The gateway doesn’t get that message.
The tx packet that is received is targeted at the second RX_SLOT: exactly two seconds after receiving the last byte (rxpk.tmst + 2000000) and using another frequency (869.525 Mhz instead of 868.1Mhz)
Why doesn’t my gateway get a txpk for the first slot?