Class C Downlinks via 7268v2 Doesnt Work w/ Built-In Server Mode

LPWAN Industrial Gateways / Concentrators
1

This problem is related to Rak11720 Class C Device not Receiving Downlink Messages - #3 by sabith-atlaslabs

I’m trying to send unscheduled downlinks to a class C device. Sending a downlink via the WisGateOS2 gui doesnt seem to work. It has been confirmed that the device is set to class C properly in the above forum question.

Here’s a video i uploaded to imgur: Imgur: The magic of the Internet

  1. first im showing that it’s a class c device
  2. im showing that i can send uplinks
  3. im showing that im trying to schedule multiple downlinks but they’re cleared immediately
  4. finally im showing that even after trying to schedule downlinks i dont receive any messages after an uplink
2

You can check the device class configuration in the terminal using:

AT+CLASS=?

To change to device class C, enter

AT+CLASS=C

Also you may want to check whether your device’s RX2DR setting matches the one configure by in the gateway using

AT+RX2DR=?
3

Hey Chris, the device is in Class C Mode, I’m using the AS923 region so AT+RX2DR returned 2, here’s the code that im running on my rak11720 device (check the previous post for more details):

void recvCallback(SERVICE_LORA_RECEIVE_T * data) {
    if (data->BufferSize > 0) {
        Serial.println("Something received!");
        for (int i = 0; i < data->BufferSize; i++) {
            Serial.printf("%x", data->Buffer[i]);
        }
        Serial.print("\r\n");
    }
}

void setup()
{
    Serial.begin(115200);
    delay(2000);
  
    Serial.println("RAKwireless LoRaWan Multicast Example");
    Serial.println("------------------------------------------------------");

    int ret;
    if(api.lorawan.nwm.get() != 1)
    {
        Serial.printf("Set Node device work mode %s\r\n",
            api.lorawan.nwm.set() ? "Success" : "Fail");
        api.system.reboot();
    }

    // OTAA Device EUI MSB
    uint8_t node_device_eui[8] =
        { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x88 };
    // OTAA Application EUI MSB
    uint8_t node_app_eui[8] =
        { 0x0E, 0x0D, 0x0D, 0x01, 0x0E, 0x01, 0x02, 0x0F };
    // OTAA Application Key MSB
    uint8_t node_app_key[16] =
        { 0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, 0xAB, 0xF7, 0x15,
        0x88, 0x09, 0xCF, 0x4F, 0x3E };
  
    /**LoRaWan Multicast Session*/
  
    uint8_t node_mc_address[4] = { 0x01, 0x02, 0x03, 0x04 };
    uint8_t node_mc_AppSKey[16] =
        { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x01, 0x02, 0x03,
        0x04, 0x05, 0x06, 0x07, 0x08 };
    uint8_t node_mc_NwkSKey[16] =
        { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x01, 0x02, 0x03,
        0x04, 0x05, 0x06, 0x07, 0x08 };
  
    // RAK_LORA_McSession session = {
    //     .McDevclass = 2,
    //     .McAddress =
  	//         node_mc_address[0] << 24 | node_mc_address[1] << 16 |
  	//         node_mc_address[2] << 8 | node_mc_address[3],
    //     .McFrequency = 923000000,
    //     .McDatarate = 2,
    //     .McPeriodicity = 0,
    //     .McGroupID = 2,
    //     .entry = 0,
    // };
    // memcpy(session.McAppSKey, node_mc_AppSKey, 16);
    // memcpy(session.McNwkSKey, node_mc_NwkSKey, 16);
  
    if (!(ret = api.lorawan.appeui.set(node_app_eui, 8))) {
        Serial.printf("LoRaWan Multicast - set device EUI is incorrect! \r\n");
        return;
    }
    if (!(ret = api.lorawan.appkey.set(node_app_key, 16))) {
        Serial.printf("LoRaWan Multicast - set application EUI is incorrect! \r\n");
        return;
    }
    if (!(ret = api.lorawan.deui.set(node_device_eui, 8))) {
        Serial.printf("LoRaWan Multicast - set application key is incorrect! \r\n");
        return;
    }
    /*************************************
     *
     * LoRaWAN band setting:
     *   EU433: 0
     *   CN470: 1
     *   RU864: 2
     *   IN865: 3
     *   EU868: 4
     *   US915: 5
     *   AU915: 6
     *   KR920: 7
     *   AS923: 8
     *
     * ************************************/
  
    if (!(ret = api.lorawan.band.set(8))) {
        Serial.printf("LoRaWan Multicast - set band is incorrect! \r\n");
        return;
    }
    if (!(ret = api.lorawan.njm.set(RAK_LORA_OTAA))) {
        Serial.printf("LoRaWan Multicast - set network join mode is incorrect! \r\n");
        return;
    }
    if (!(ret = api.lorawan.deviceClass.set(RAK_LORA_CLASS_C))) {
        Serial.printf("LoRaWan Multicast - set device class is incorrect! \r\n");
        return;
    }
  
    if (!(ret = api.lorawan.join())) {
        Serial.printf("LoRaWan Multicast - join fail! \r\n");
        return;
    }
  
    /**Wait for Join success */
    while (api.lorawan.njs.get() == 0) {
        Serial.print("Waiting for Lorawan join...");
        api.lorawan.join();
        delay(10000);
    }

  // // Get device address
	// api.lorawan.daddr.get(node_mc_address, 4);
	// // Add address to MC sessionZ
	// session.McAddress = node_mc_address[0] << 24 | node_mc_address[1] << 16 | node_mc_address[2] << 8 | node_mc_address[3];


    api.lorawan.adr.set(true);
    api.lorawan.rety.set(1);
    api.lorawan.cfm.set(1);
  
    api.lorawan.registerRecvCallback(recvCallback);
    /**LoRaWAN Multicast Setting*/
    // if (api.lorawan.addmulc(session) == true) {
    //     Serial.println("Add Multicast Success");
    // } else {
    //     Serial.println("Add Multicast Fail");
    // }
}

void loop()
{
}
4

Hey Chris

Looks like it works now, same code, gateway and everything. The only explanation I can think of is that the gateway was too close, can this be a problem? They were about 30-60cm away from each other on my desk.

Thanks