The meter as delivered
| Parameter | Value |
|---|---|
| LoRaWAN | Version 1.0.3, class C |
| Frequency band | EU 863–870 MHz |
| Join mode | OTAA |
| JoinEUI (formerly AppEUI) | 10 2C EF 00 00 00 00 00, the same for all meters |
| DevEUI | starts with 10 2C EF, individual, readable on the display |
| AppKey | individual, readable on the display |
| Data rate | adaptive (ADR) |
You find DevEUI and AppKey on the meter in the LoRa menu. If a network does not support class C devices, the meter works as a class A device.
Step 1: register the device in TTN
- In the TTN console, open the application and add an end device.
- Select the EMU Professional II LoRa from the device repository and set the frequency plan Europe 863–870 MHz.
- Enter JoinEUI 10 2C EF 00 00 00 00 00.
- Copy DevEUI and AppKey from the meter display.
- Save the device. The meter tries to join within a random window of up to ten minutes.
Whether the join worked is shown on the meter under «LoRa JoinStatus»: «Joined» with the timestamp of the last uplink. «LoRa Status» shows RSSI, SNR and spreading factor.
Step 2: set up the decoder
EMU provides the decoder for TTN and ChirpStack on GitHub, together with a generator for downlinks. Entered as uplink formatter in the application, it converts the packets into readings.
| Packet | fPort | Content |
|---|---|---|
| First packet after the join | 100 | Serial number, meter type, current and voltage transformers, MID year |
| Default uplink | 1 | every 15 minutes: active energy import and export, tariff 1 and 2, with timestamp |
| Time synchronisation | 100 | DeviceTimeReq without readings |
The values come from the meter’s load profile memory and carry the timestamp of the entry. The byte order is little endian.
Step 3: change readings and interval by downlink
Which values are sent at which interval is set by downlink. There are ten profiles on fPorts 1 to 10 with up to ten readings each; lower fPorts take priority. The interval ranges from 1 minute to 45 days.
Example from the manual: set the transmission interval to 1 minute, without acknowledgement, profile active. The packet goes to the fPort of the profile to be changed:
01 00 08 53
01 00 interval 1 minute (little endian)
08 flags: no acknowledgement, no re-join, profile active
53 CRC-8Below 15 minutes, the meter’s load profile interval must also be shorter, otherwise the same values arrive several times. If the packet is too large for the available airtime, it is transmitted only partly or not at all. The downlink generator on GitHub calculates the CRC-8.
Operation
- The meter checks at least once a day whether it is still connected to the network and rejoins on its own if necessary. This also allows it to be moved to another LoRaWAN network.
- It synchronises its clock via the LoRa network, at least once a day.
- The gateway can still be moved after installation. The adaptive data rate adjusts the transmission parameters.
- The meter has been tested with The Things Network and ChirpStack.
Order numbers
| Version | Article number | Shop |
|---|---|---|
| EMU Professional II 3/100 LoRa – direct connection 100 A | P20A000LO | Shop: EMU Professional II 3/100 LoRa P20A000LO → |
| EMU Professional II 3/100 LoRa ext. antenna – direct connection 100 A | P20A000LE | Shop: EMU Professional II 3/100 LoRa ext. Antenne P20A000LE → |
| EMU Professional II 3/5 LoRa – CT connection | P21A000LO | Shop: EMU Professional II 3/5 LoRa P21A000LO → |
| EMU Professional II 3/5 LoRa ext. antenna – CT connection | P21A000LE | Shop: EMU Professional II 3/5 LoRa ext. Antenne P21A000LE → |
Order online in the EMU Metering shop.