# Get data from TTI via Node-RED from multiple gateways

**URL:** <https://discourse.nodered.org/t/get-data-from-tti-via-node-red-from-multiple-gateways/41898>\
**Category:** General\
**Created:** [2 March 2021 14:24 UTC](https://discourse.nodered.org/t/get-data-from-tti-via-node-red-from-multiple-gateways/41898 "2021-03-02T14:24:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![wiesel](https://avatars.discourse-cdn.com/v4/letter/w/ad7895/32.png) [@wiesel](https://discourse.nodered.org/u/wiesel)\
**Post date:** [2 March 2021 14:24 UTC](https://discourse.nodered.org/t/get-data-from-tti-via-node-red-from-multiple-gateways/41898/1 "2021-03-02T14:24:35Z")

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![flow](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/d/cde6681ac7ff7521833f66bad6552881cb761ea3.png)

I’m testing a couple of LoRaWAN gateways to find out which one has the best rssi/snr.

I have made this function in Node-RED called "get specific data"

var msg1 = {

```
payload: {
    gtw: msg.payload.uplink_message.rx_metadata[0].gateway_ids.gateway_id,
    eui: msg.payload.uplink_message.rx_metadata[0].gateway_ids.eui,
    received_at: msg.payload.uplink_message.received_at,
    PacketFromTTI: msg.payload.uplink_message.frm_payload,
    snr: msg.payload.uplink_message.rx_metadata[0].snr,
    rssi: msg.payload.uplink_message.rx_metadata[0].rssi

```

}

}

var msg2 = {

```
payload: {
    gtw: msg.payload.uplink_message.rx_metadata[1].gateway_ids.gateway_id,
    eui: msg.payload.uplink_message.rx_metadata[1].gateway_ids.eui,
    received_at: msg.payload.uplink_message.received_at,
    PacketFromTTI: msg.payload.uplink_message.frm_payload,
    snr: msg.payload.uplink_message.rx_metadata[1].snr,
    rssi: msg.payload.uplink_message.rx_metadata[1].rssi

```

}

}

var msg3 = {

```
payload: {
    gtw: msg.payload.uplink_message.rx_metadata[2].gateway_ids.gateway_id,
    eui: msg.payload.uplink_message.rx_metadata[2].gateway_ids.eui,
    received_at: msg.payload.uplink_message.received_at,
    PacketFromTTI: msg.payload.uplink_message.frm_payload,
    snr: msg.payload.uplink_message.rx_metadata[2].snr,
    rssi: msg.payload.uplink_message.rx_metadata[2].rssi

```

}

}

return [msg1, msg2, msg3]

My challenge is that I have hardcoded what the 3 gateways at the office receive (rx\_metadata). But the plan is to walk around the area with a field tester, and I don’t know if any other gateways are nearby. So I somehow need to find the amount of elements in rx\_metedata, and send everything to the csv file.

---

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [1 May 2021 14:25 UTC](https://discourse.nodered.org/t/get-data-from-tti-via-node-red-from-multiple-gateways/41898/2 "2021-05-01T14:25:16Z")

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