Trouble getting an Eastron SDM630 meter to send data


I’m having real trouble getting an Eastron SDM630 meter to send any data to my gateway.
I have triple-checked DevEUI, AppEUI and AppKey.
I have also numerous re-link attempts – the meter keeps telling me that it is successfully linked to the gateway.
So finally I contacted Eastron Europe who put me onto someone technical who told me that I was missing a downlink to send to the meter. This would then result in the meter sending its data every 30 minutes. I was sent the hex downlink, entered it and, again, triple-checked it. All seems correct - but still no data being sent uplink from the gateway (having waited over an hour).

The only thing I can think is that the downlink packet isn’t being sent to the correct LoRa FPort. I’ve tried the same port I used for a Watteco sensor (125) but perhaps that’s wrong. Does anyone know the correct FPort to send downlinks to Eastron ? Or can you suggest what else I might try ?

Many thanks in anticipation

How does it know? Nodes connect to the network (server) not GW’s - they have no way of knowing who or what is talking to them or who is listening - only info in the LNS can tell you that.

Shooting in the dark and a brute force mechanism - literally hundreds of FPorts - what does the

tell you to use?

What do you see on the GW console when starting the meter and attempting to join or otherwise communicate with the network?

The “someone technical” didn’t tell me which FPort to use – that’s one of the issues. And yes I realise that trying 224 different ports is brute force, but I have no other avenues open to me right now given my current LoRa knowledge.

The last time I uploaded the configuration to my hub, I got this:


And what is “this”? Where is it from? What does it tell us to help you resolve this?

Strip it right back to the basics:

  • Is the device configured for OTAA or ABP?
  • What do you see in your gateway console on TTN?
  • What do you see in the device console on TTN?

Until you (we) are sure that the device is connected to the network (it does NOT connect to the gateway), sending a configuration downlink is pointless.

Does the device have a serial console that you can connect to, to see what’s going on?

Do you have a link to the device manual(s).

If any of this is unfamiliar, please read

If your RSSI is -21 then your node is to close to your gateway, you need 10m plus and a brick wall between your gateway and node, you are aiming for -55 to -65 max RSSI.

LoRaWAN (Long Range Wide Area Network ) a few meters are to close.

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Or perhaps pass the configuration issues of the sensor you bought from Eastron, back to Eastron.

They do appear to be selling it as a ‘LoRaWAN’ sensor so one might expect them to support it.

If it dont work, and they wont support it, send it back ?

WHich hub? WHere is this from?

Note if you are seeing -21dbm RSSI then sad to say THEY ARE SHOUTING AT EACH OTHER! and likely even if GW decodes/forwards ok without distortion induced CRC errors or channel bleed likely the response back from GW to Node also overloading etc front end causing similar issues. Recommend min 3, pref 10 meters distance and even then best with some absorber in between - wall, thick window etc. look for RSSI to be in range -65 - -110 when debugging worst case -50 --115 then you know you are not battling self induced RF issues vs configuration & set-up problems

Have you asked? What does documentation tell you? Or have you lost contact details? did you get through to them last time? Try again?

Hi everyone,

I have one “SDM630MCT-Lora” and maybe I can help.
So, let me start by saying that I strongly recommend anyone reading this to avoid this device. It’s been a nightmare to deal with their documentation and with their support.

The documentation on downlinks is also extremely lacking (as of date, they just mention the possibility of the “Active Upload Mode” but no explanation on how to actually activate it, except for asking to them).

After a long torture, I’ve been able to get some example downlinks from cThings (one of their resellers).
Here’s what I know so far:

fPort: 1
The device must be set as a Class C device on your network server

Their example downlinks:

Downlinks for L1 Current every 10 mins
01 03 00 18 00 02 44 0C
01 10 00 18 00 02 04 44 7A 00 00 C6 2C
01 03 00 0E 00 02 A5 C8
01 10 fe 12 00 01 02 00 05 7a ee
01 10 fe 02 00 0f 1e 07 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 65 a7
01 10 fe 01 00 01 02 00 0a 38 49

Downlinks for L1, L2 and L3 Current every 5 mins
01 03 00 18 00 02 44 0C
01 10 00 18 00 02 04 44 7A 00 00 C6 2C
01 03 00 0E 00 02 A5 C8
01 10 fe 12 00 01 02 00 05 7a ee
01 10 fe 02 00 0f 1e 07 08 09 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 9a d7
01 10 fe 01 00 01 02 00 05 78 4d

Downlinks for L1 Current, L1/N Voltage, Phase angle, kWh, Reactive Power & Apparent Power every 1 min (not recommended)
01 03 00 18 00 02 44 0C
01 10 00 18 00 02 04 44 7A 00 00 C6 2C
01 03 00 0E 00 02 A5 C8
01 10 fe 12 00 01 02 00 06 3a ef
01 10 fe 02 00 0f 1e 07 00 1c 3a 14 18 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 52 e9
01 10 fe 01 00 01 02 00 01 79 8e

Things you might notice (and that I had to understand myself, they didn’t explain me anything despite me asking multiple times):

  • 6 downlinks for a basic setting. Incredible. I’m still not sure what the first 4 do, they don’t seem to be necessary.
    • The first three downlinks are identical (“The first three are opening settings”, no idea what this means)
    • The fourth downlink seems to be for setting the amount of variables to send (“four is setting number of parameters”). Unclear why with both 1 and 3 variables you’d use “05”, and with 6 you’d use “06”.
  • The final two bytes of every downlink is a Modbus CRC-16 (can be easily calculated plugging the rest of the message, excluding the CRC, into this remember that it’s ‘Big Endian’)
  • “01 10 fe 02 00 0f 1e” seems to be the prefix to start setting the variables that should be sent. This is followed by the modbus registry index of each variable that should be included, + padding “ff” to get to a total of 30 variables. (you can use this reference for the ids: What parameters are available for the Eastron SDM630MCT-LoRa Electricity Meter? | cThings Support)
  • “01 10 fe 01 00 01 02 00” seems to be the prefix to set the interval of data upload, followed by the frequency expressed in minutes (e.g. “05” = every 5 minutes, “0a” = every 10 minutes, “01” = every minute).

For the decoding of the uplink, this reference is good too: Decoding data from the Eastron SDM630MCT-LoRa | cThings Support

If you have more than 5 variables set for active upload, you’ll receive multiple messages with an incremental number (01 for the first message, 02 for the second etc., this is explained in the documentation).

You could make a number of additional observations on the device, like the fact that they waste space for device serials in uplinks which is useless given the DevEUI, the redundant CRC, the ASCII encoding (even if this point is weird, I’m sending Hex downlinks and it worked fine).

I hope this can be helpful.

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Hi, thank you for sharing this information. If I had read them a month ago I would have saved myself a lot of trouble. Allow me to add a few side notes on downlinks since I understood, perhaps, something more.

  1. The first command
    01 03 00 18 00 02 44 0C
    is used to say that you are about to send the password.

  2. The second sends the password (it’s a modbus request to write to multiple registers).

  3. The third reads the status of the password (ie 0/1 if the device is unlocked or not).

  4. The fourth package is the strangest one, I didn’t understand if in fact it is used to write how many variables we want or on how many registers we are going to write the addresses of the variables we are interested in (the difference is subtle but substantial). If it were the second option, each time we would have to delete (by writing FF) the registers that don’t interest us.

Having said that the device seems very poorly supported and I would recommend avoiding it. However, the alternatives cost double, if you have something to suggest I’m ready to listen to you.
Thank you

For any doubts we can continue this conversation. I seem to have found the first person on the WEB who understood how to use this thing, now I no longer feel alone

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Very helpful explanation. Thank you too! (same feeling, are we alone? :rofl:).
I’ll keep you posted as we use the device a bit more.

Honestly, I don’t have many suggestions on the devices because we are looking for good alternatives as well. One option we are thinking of is to have an hack: traditional modbus RS485 meter for which you have many alternatives (incl. this one but without Lora) + a good quality and documented Modbus-Lora converter (e.g. Dragino). But yeah, the price is way higher.

Do you know any more expensive all-in-one alternative which is focused on LoRa?

It’s funny because I had already implemented the 630 Modbus version with the Dragino in the middle to communicate LoraWan but honestly it’s starting to become onerous in terms of management and costs. This is what I found instead:

They asked me for 172 euros a piece.
A little too much and by now I think I understand how this Eastron Lora works, I don’t feel like wasting these tears and this blood shed

Interesting, do you perhaps have the documentation of that / know which variables they can export?
The Eastron can export a lot of stuff (phase angle etc.)

Honestly i really didn’t search for it, but they seems to have a good support (I e-mailed them). If you cannot find online you can write to them.

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Could you please help me to manage SDM630MCT-LoRa data?

From the message above:
Downlinks for L1, L2 and L3 Current every 5 mins:
01 03 00 18 00 02 44 0C
01 10 00 18 00 02 04 44 7A 00 00 C6 2C
01 03 00 0E 00 02 A5 C8
01 10 fe 12 00 01 02 00 05 7a ee
01 10 fe 02 00 0f 1e 07 08 09 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 9a d7
01 10 fe 01 00 01 02 00 05 78 4d

What info except the 30 bytes and CRC-16 is the same for all counters? Or is there specific info like passwords, etc.?
We need to try two options to start with:

  1. 2F only (Total kWh) every 5 min.
  2. 2F (Total kWh), 00 (L1-N Voltage), 01 (L1-N Voltage), 02 (L1-N Voltage) every 5 min.

What specifically needs to be sent to the meter in both of these cases? Which port (port no.) to send to?
We are using a ChirpStack Network server.

One more question.
What are the specific parameters that our meter sends by default?
Because it does send, just according to what I find on the internet not in the manufacturer’s descriptions, it varies. There is no info about default message in the manufacturer’s descriptions.

Thank you in advance.

Putting the exact same post twice isn’t very helpful - if you need to alert someone to a post, the best way is to put an @ in front of their user name - like this → @IrmantasK

If you are in a hurry, please be aware that it’s all volunteers here, please do not duplicate this post somewhere else on this forum, you will just have to be patient.

So off topic for the TTN Forum, funded by TTI !

Tempted to close thread, but that would be dis-service to other TTN/TTI users…

@moderator_team suggestions for this question/portion? - leave/delete/part of general knowledge/other?

Good spot, I was too exercised by the double post and that fact that it is an Eastron unit which we all know are made by evil pixies out to thwart even the most technical users. On the basis that if there was going to be any expertise in the world to solve this, the TTN community do seem to be making very slow progress getting such issues solved, but solutions do come up. So let it stand but @IrmantasK needs to keep Chirpstack out the discussion and perhaps tell us what the manufacturer said when they contacted them.


ok. Everything just about Eastron.

Hi, could you please help me with my questions about Eastron in my message below?

Did you read @frappe994’s last post: