Up to 20 meters can be read and mapped to Modbus Registers
Serial Interface
Freely selectable serial interface for each meter in list
RS232
RS485
Baud Rate
Freely selectable start baud rate for each meter in list
300
600
1200
2400
4800
9600
19200
38400
57600
115200
Table Code
Freely selectable reading table code for each meter in list
Init String Count and String Itself
Freely definable init string for each meter in list
If meter needs an init string to "wake up", user can define the string itself and number of times that it will be sent
Query Interval
Freely selectable query interval for each meter in list
That depends on meter reading list, since each meter will be read 1 by 1 over RS485 bus (or directly from RS232), reading interval depends on number of meters in list and read out reading time for each meter (based on its read out list)
Time Out
Freely selectable time out value for each meter in list
LKM will continue with next meter in list in case there is no response from meter in predefined time out duration
OBIS Codes
Up to 48 OBIS codes can be defined and enabled to be read from all meters in list
User can open 2 web pages side by side and check readout list from meter and simply add OBIS codes to LKM as per need

LoRa TECHNOLOGY

Based on 
STM32L151CxU6Axx
Pre-Certified according to EN 300 220
Sensitivity 
Down to -138 dBm
Link Budget 
Up to 156 dB
Communication Distance 
Up to 15km (Line of Sight)
Typical Communication Distance Indoor/Urban
>2km
LoRaWAN Activation Options 
Activation Over Air (OTAA)
Activation by Personalization (ABP)
User Selectable
LoRaWAN Port
User Selectable
Adaptive Data Rate
Available
Uplink Data Rate 
SF12 / 125 kHz / 250 bps
SF11 / 125 kHz / 440 bps
SF10 / 125 kHz / 980 bps
SF9 / 125 kHz / 1760 bps
SF8 / 125 kHz / 3125 bps
SF7 / 125 kHz / 5470 bps
SF7 / 250 kHz / 11000 bps
FSK 50k / NA / 50000 bps
Tx Power Level 
0 to 16dBm Configurable
LoraWAN Class 
Class A
Class C
LoraWAN Data Send
Interval defined by user
Data Format as Modbus Frame
Send OBIS Code Details as Status Message At Start Selectable
ETHERNET SWITCH TECHNOLOGY
Ethernet Standards 
IEEE 802.3 for 10Base-T
IEEE 802.3u for 100Base-T(X)
IEEE 802.3x Flow Control
Mac Table 
1K MAC address entry
Processing 
Store-and-Forward
Memory 
448K bits packet buffer memory

LoRaWAN DETAILS
Message sent to LoRaWAN Port number 1 in every connection to LoRaWAN Server
4 Bytes: LKM Device Id
1 Byte: Frame Type (Lower 4 bits) and Package Number (Upper 4 bits). If Package Number is 1 or more that means the package splitted.
0x00 : means status package for device status and package is the first package
1 Byte: Number of Meters configured to be read
1 Byte: Number of OBIS Codes configured  to be read
1 Byte: LoRaWAN Port of the package
4 Bytes: RTC Time
3 Bytes: LKM Device firmware version
N Bytes (maximum 22): LKM Device name configured by user
Status Message - OBIS Details
Message sent to LoRaWAN Port number 1 in every connection to LoRaWAN Server if enabled by user
4 Bytes: LKM Device Id
1 Byte: Frame Type (Lower 4 bits) and Package Number (Upper 4 bits). If Package Number is 1 or more that means the package splitted.
0x01 : means status package for OBIS details and package is the first package
OBIS Frames are shared 1 by 1 in following format, qty is given in Device Status message
1 Byte: OBIS Code Number in same sequence configured from web interface
1 Byte: Hexadecminal character 0x1F as seperator character
N Bytes (maximum 15): Configured OBIS Code itself like "1.8.0", each character in ASCII format
1 Byte: Hexadecminal character 0x1F as seperator character
....Next Obis Frame that maximum payload size allows.

Meter Data Message - Parsed from Meter Reading
Message sent to LoRaWAN configured port and minimum send interval can be configured by user
4 Bytes: LKM Device Id
1 Byte: Frame Type (Lower 4 bits) and Package Number (Upper 4 bits). If Package Number is 1 or more that means the package splitted.
0x02 : means meter data package and package is the first package
1 Byte: Read Meter number in same sequence configured from web interface
1 Byte: Data Starting OBIS Code Number in same sequence configured from web interface
1 Byte: Total Data Size in Payload
Meter Data Frames are shared 1 by 1 in following format, each data is 4 Bytes
4 Bytes: Meter Data
....Next data that maximum payload size allows.

MODBUS DETAILS
Up to 20 meters can be read and mapped to Modbus Registers
Up to 48 OBIS values can be mapped into Modbus Registers
Gateway Modbus Address
Default value is 1
User can change from web interface
Modbus Data and Addresses
Data can be read via Function Code 3
Read Holding Registers (4x)
all registers are "long" data

Adress of 1st Meter Data:
Hex: 0x00 00
Decimal: 0
Quantity: 96 (only available if 48 registers are enabled, it changes based on enabled regsiters quantity)
Adress of 2nd Meter Data:
Hex: 0x01 00
Decimal: 256
Quantity: 96 (only available if 48 registers are enabled, it changes based on enabled regsiters quantity)

Adress of 3th Meter Data:
Hex: 0x02 00
Decimal: 512
Quantity: 96 (only available if 48 registers are enabled, it changes based on enabled regsiters quantity)

.....

Adress of 20th Meter Data:

Hex: 0x13 00
Decimal: 4864
Quantity: 96 (only available if 48 registers are enabled, it changes based on enabled regsiters quantity)

MQTT DETAILS
MQTT Publisher can be enabled and can be used in parallel with Modbus conversion (or stand alone)
MQTT Connection
Broker IP and Port can be entered
Client ID , User name and Password can be set
Publish Topic and Subscribe Topic can be defined from web interface
Data Send Interval
User can send Data send interval in seconds
Default is 60 seconds and LKM will send meter data to MQTT server in that interval
NTP Server
NTP server time will be added to each MQTT message
Data Format
There are 2 predefined formats
OBIS Values As Objects: Sends OBIS values and then mapped values in ASCII readable fromat
OBIS Values as Modbus Frame: Send just like the response of Modbus query as hex data (smaller data size)

Meter Communication Status
User can see reading status of each meter in reading list
Last Query Time and Last Serial Package also available in this list
Modbus Communication Status
User can see reading status of each Modbus client connected
Last Query Time and Last Received and Sent Packages also available in this list
Meter Reading to Modbus Mapping (Gateway) Status
User can see modbus mapping status of each meter in reading list
Data can be checked in realtime or status can be set for any specific meter in list
Ex: Show mapping status of Meter Number 2 in meter reading list only
Meter Reading Status
User can see IEC reading details in real time
This data can help to select desired OBIS codes
LoRaWAN Status
User can see LoRaWAN Network Status (Joining or Active) 
LoRaWAN Tx and Rx Messages
Latest sent data package details
Number of LoRaWAN Messages sent, pending and lost
Duty Cycle Block Time

SMA Antenna Connector for LoRa
1 Standard SMA female interface, 50 ohm
Console Port
Micro USB or USB Type-C connection for LOG in 115200 baud
10/100T(X) RJ45 Ports
Ethernet Connection on 2 ports
Serial Ports
5 pin wired Terminal Connection
Tx, Rx, GND for RS232
A and B for RS485
Reset Buttons
Reset to Client and Reset to Server Operating modes buttons

Power indicator
Power LED
10/100T(X) Indicators
Activity LEDs:
ETH1, ETH2 and LKM (Activity of device itself)
System Indicators
Status LED,
Tx and Rx of data LEDs and Server LED
(LED ON: Server Operating Mode, LED OFF: Client Operating Mode)
Console Indicators
Tx and Rx of data LEDs

Input Range
5-48V DC wide range Power Input
(Allows up to 60 V DC)
Reverse Polarity Protection
Available
Thermal Shutdown and Current Limit Protection
Available

Enclosure
Metal, IP 40
Dimensions
43 x 95 x 124 (w x d x h) mm
Weight 
~400gr
Storage Temperature
-65 to 150 °C
Operating Temperature
-40 to 85 °C 
Operating Humidity
5% to 95%Non-condensing