How to change TX power of gateway rak2247

tuyenpham · May 27, 2020, 4:32am

Dear all,
I saw in LORAWAN FRAME in chirpstack server always show Tx power = 10 while rak2247 had 27 dBm. How can we increase this to maximum it? I tried change rf_power feild in file global_config.json but it seem not effect.

regards,
Tuyen

Nicholas · May 27, 2020, 7:32am

yes，The maximum tx_power is 27dbm, but you are showing the rf_power.These two are different.

tuyenpham · May 27, 2020, 9:08am

Thanks Nicolas,
How to check currently tx power setting of gateway?

regards,
Tuyen

Nicholas · May 27, 2020, 10:36am

You can receive power from server log,it will select the nearest power to send.

tuyenpham · May 27, 2020, 1:38pm

thanks Nicholas,
I checked in my side and it show powe = 10

How to change it to maximum? I’d like to archive a long range over 5km

regards,
Tuyen

Nicholas · May 28, 2020, 1:14am

It is adaptive, the server will have the function of automatic regulation, gateway according to the server issued by the power to select its support.

tuyenpham · May 28, 2020, 2:55am

Hi Nicholas,
I am using local Chirpstack server from https://downloads.rakwireless.com/LoRa/RAK2247-Mini-PCIe/RPi-Frimware/RAK2247-USB_Latest_Firmware.zip
Can you show me how to change it on sever?
thanks and regards,
Tuyen

Nicholas · May 28, 2020, 2:58am

The instructions issued by the server can not be controlled, can only be adaptive, you can try remote or different shielding test.

Nicholas · May 29, 2020, 6:54am

News，I hope I can help you！

We can’t modify power on server.

But we can modify the gateway’s global_conf.json file so that the gateway can only send at maximum power.
You can see tx_lut_xx information in the file
/opt/ttn-gateway/packet_forwarder/lora_pkt_fwd/global_conf.json.
Delete the content of tx_lut_0 to tx_lut_14, only keep the content of tx_lut_15, and change the name of tx_lut_15 to tx_lut_0, then restart the gateway, the gateway will only send at maximum power.

Your gateway firmware version must be 4.2.0 or later. If the gateway firmware version is less than 4.2.0, please download the latest version of the gateway firmware.

tuyenpham · May 29, 2020, 3:49pm

Thanks Nichoas,
How i can check version of rak2247?

regards,
Tuyen

tuyenpham · May 29, 2020, 4:04pm

Hi Nicholas,
I checked my gateway version, it show
Raspberry Pi 3 Model B Rev 1.2, OS “10 (buster)”, 4.19.75-v7+.
RAKWireless gateway RAK2247 for USB version 4.2.0R install from firmware.
Gateway ID: B827EBFFFECA14EC.
I deleted tx lut 0 to 14 and change name 15 as below

I seem no effect. on server side still show power = 10

anything wrong here?

thanks,
Tuyen

tuyenpham · May 30, 2020, 4:06am

Thanks Nicholas,
You are right, I tested and saw rssi increase quite big than before.

thanks for your support,
Tuyen

tuyenpham · July 6, 2020, 4:07pm

Hi Nicholas,
My bad, I saw rak2247 only support to 25dbm

So I need to change global_config.json to 25dbm instead 27dbm, right?

Can you confirm on your side after change to maximum then tx power also change in lorawan frame to 25?

regards,
Tuyen

Nicholas · July 7, 2020, 1:13am

The server sends power=14, but the bottom of the log selects the closest value in the configuration file, which must be 4.2.0 and later.