LoRa Optical Meter Interface


The SRLR4302 is a meter interface designed to read energy data from the optical port of meters supporting either the SML or IEC 62056-21 protocols. Since there is no power available directly from the optical port, the SRLR4302 can be powered either via 3 LR6 batteries, or alternatively using an external 5VDC power supply via the micro USB-B.

User Interface


Since the device is primarily battery driven the LED is turned off by default. The LED will display the meter connection status either on startup, or after a button press. The status will be shown for 4 seconds before turning off again.

StatusTiming cycleDescription
Offn/aNo power; system reset pending
Fast Blink0.2 secMeter locked, unable to receive all relevant meter data
Slow Blink1 secMeter connection OK; no SmartBridge connection
Strobe0.04 secMeter connection Error
Solid onn/aConnected with meter and SmartBridge, all is operational


The user button has multiple functions as shown in the table. The function is selected depending on the length of time the button is held.

Button holdDurationAction
None< 2 secDisplay LED meter status, transmit status message
Short> 2 sec & < 10 secReset PIN entry count & attempt new entry immediately if not already in progress
Long> 10 secDevice Reset, after more than 10 seconds after restart
Long> 10 secFactory reset, in the first 10 seconds after restart



In most cases the device requires no special meter commissioning beyond attaching the optical probe to the front of the meter. It is important to take care that the optical probe is correctly aligned, with the cable pointing vertically downwards.

For installations where the power data is required, then the SRLR4302 should automatically “unlock” the optical meter interface to provide the extended data set (including power) when the PIN code is provided via the connected gateway. For some meter types, this is not possible and the meter must be unlocked manually by the user. In these cases this should be indicated to the user via the app.

LoRa Gateway

When commissioning the LoRa link to the NET2GRID LoRa gateway (e.g. SPLR4911) there is no special action required from the user, other than powering on the SRLR4302 and connecting the optical probe to the meter. The user should be informed of the required steps via the app, but in general the only important detail is that the gateway (SPLR4911) should be onboarded to the WiFI network and be connected to the platform account before powering on the SRLR4302.

Further technical details regarding the LoRa commissioning process please refer to the LoRa commissioning section.