EthMBus-3SL SECURE
Base line
Ethernet to M-Bus communication converter
Ethernet converter with secure communication
Designed for remote secure communication with M-Bus meters using the Ethernet computer network in building or home automation and similar applications.
The converter works only as a transparent gateway for transfer of M-Bus messages using TCP or UDP Ethernet protocols. These protocols can be secured through encryption to ensure data confidentiality and integrity. Data from meters is therefore not visible and cannot be altered or tampered with during transmission over the Ethernet network. Data is available only through M-Bus protocol readout.
Main characteristics
M-Bus port
- Connection of 1 to 3 M-Bus slave devices.
The most commonly used devices are heat, water, gas and electricity consumption meters. - Surge protection with standard level of protection against overvoltage.
- Current protection against overload and short circuit on the communication line with LED status indication.
Power supply
- Wide power supply operating ranges of 8.5-36V DC and 8-26V AC (converter version 4 and higher).
- Overvoltage protection.
- LED power supply indication.
Ethernet
- TCP, UDP,TCP/AES, UDP/AES, SSH and SSL/TLS protocols and virtual COM port software.
- 10/100BASE-TX ethernet port, RJ45 connector.
Security
- SSLv3 and SSHv2 in client-server mode, configurable certificate bit length
- AES, 3DES, and RC4 encryption
- SHA-1, MD5 authentication, user access list
- Supports TLS only up to TLS v1.2
Mechanical construction
- Plastic box for mounting on a 35 mm DIN rail.
Main software characteristics
Transparent gateway mode:
- TCP/IP connection in server mode.
- TCP/IP connection in client mode – supports multiple simultaneous connections or their fallback backups.
- UDP connection in single or multiple clients mode.
Software functions
- Converter configuration only through HTTP/HTTPS web interface or by uploading an XML file.
- TCP and UDP communication in server and client modes with encryption and authentication options.
Main differences from the EthMBus-3SL SMART converter
- No SMART functions for independent readout, processing and export of M-Bus data.
- Higher power consumption.
- Support for multiple connections in TCP/IP client mode.
- HTTPS zabezpečená konfigurácia cez webové rozhranie
- Options for encrypted and secured transfer of M-Bus data.
- Doesn’t provide Telnet interface for configuration.
- Doesn’t provide logging of Ethernet activity and error states.
Guarantee of quality
- Each converter passes through several functional electrical tests during the production.
Additionally a communication test is performed after final assembly. - EMC certification in an accredited laboratory.
- Solid design and construction based on many years practical experience.
| Ethernet communications interface | |
|---|---|
| Communications interface | 10BASE-T, alebo 100BASE-TX (auto-sensing) |
| Communication protocols | ARP, UDP, TCP, ICMP, AutoIP, DHCP, HTTP, HTTPS, BOOTP, SMTP, SSHv2, SSLv3, TLS1.0-1.2 |
| Connector | RJ45 |
| Compatibility | Ethernet: Version 2.0/IEEE 802.3 |
| M-Bus Master communication interface | |
| Number of attachable devices | 1 to 3 SLAVE devices, idle current max. 4.5mA |
| Baud rate | 300 – 9600 bps |
| Protection | – overvoltage protection TVS 400W |
| – electronic protection against overloads and short circuit on the communication line | |
| note: converter can withstand short-term short circuit on the communication line | |
| Galvanic separation | up to 1kV from power supply, more than 1kV from Ethernet |
| Connector | terminal block for wires of up to 2.5 mm2 cross-section area |
| Power supply | |
| DC power supply | 8.5V to 36V |
| AC power supply ∿ | 8V to 26V |
| Maximum limits of supply voltage – permanent operation is not recommended | |
| Minimum power supply | 8V DC, 7.5V AC ∿ |
| Maximum power supply | 39V DC, 27V AC ∿ |
| Protection | overvoltage protection TVS 400W |
| Power consumption | 1.5W to 2.3W depends on load and power supply. |
| Maximum power consumption during short circuit on M-Bus line is 2.9W. | |
| Connector | terminal block for wires of up to 2.5 mm2 cross-section area |
| Status LEDs | |
| Power – blue | connected power supply indication |
| Transmit – green | indication of data broadcasting on the M-Bus line |
| Receive/Overload – yellow | indication of data reception on the M-Bus line – LED is flashing |
| indication of M-Bus line overload – LED stays on (idle current > 7.5mA) | |
| Short – red | indication of short on the M-Bus line – turned on (resistance of the line < 1kΩ) |
| Temperature | |
| Operating range | 0°C to 45°C |
| Mechanical construction | |
| Mechanical design | plastic box |
| Mounting | 35 mm DIN rail (EN 50022 top hat rail) |
| Dimensions: height x width x length | 56.5 x 17.5 x 97.5mm |
| Protection classification | IP20 |
| Weight | 52g |
EMC compatibility of the M-Bus converter has been tested according to the following standards for information technology.
| EMC emissions tests | ||
|---|---|---|
| Standard | Test | Level |
| EN 55022 | Power line – CONDUCTED EMISSIONS 10/150 kHz – 30 MHz | Class B |
| EN 55022 | RADIATED EMISSIONS (Electric Field) 30 MHz – 1000 MHz | Class B |
| EMC immunity tests | ||
|---|---|---|
| Standard | Test | Level |
| EN 61000-4-2 | ELECTROSTATIC DISCHARGE (ESD) – Contact discharge | ± 4 kV |
| EN 61000-4-2 | ELECTROSTATIC DISCHARGE (ESD) – Air discharge | ± 8 kV |
| EN 61000-4-4 | ELECTRICAL FAST TRANSIENT/BURST – Power line | ± 4 kV |
| EN 61000-4-4 | ELECTRICAL FAST TRANSIENT/BURST – M-Bus line | ± 4 kV |
| EN 61000-4-5 | SURGE IMMUNITY – Power line. Common/differential mode. | ± 1 kV / ± 0.5 kV |
| EN 61000-4-5 | SURGE IMMUNITY – M-Bus line. Cable shielding. | ± 4 kV |
| EN 61000-4-5 | SURGE IMMUNITY – M-Bus line. Common/differential mode.* | ± 1 kV / ± 0.5 kV |
| EN 61000-4-6 | CONDUCTED DISTURBANCES, INDUCED BY RADIO-FREQUENCY FIELDS 0,15MHz – 80 MHZ. Power line and M-Bus line. | 3 V |
* test performed at the manufacturer’s request. The M-Bus port of the converter features an increased surge protection. This type of testing is not required when a shielded cable is used.
End user
Price list for individuals and companies which do not buy converters for resale.
Integrator
Price list for companies which buy converters for the purpose of resale to their custommers as manufacturers or suppliers.
The price list is available only to registered business partners.
Registration request.
Leaflet
Name / File
Date
Size
Manuals
Name / File
Date
Size
Manual of network connections for SECURE converters
EthMBus_SECURE_connections_guide_v1_31_EN.pdf
Date:
5. 2. 2026
Size:
456 kB
Lantronix utilities
Name / File
SW application from Lantronix for advanced configuration of the converters
https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/106070471/Latest+version+of+DeviceInstaller
SW application for creating a virtual COM port from Lantronix
https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/106856722/Latest+version+of+the+SCPR+Secure+Com+Port+Redirector
SW application for creating a virtual COM port from Lantronix
https://papouch.com/lantronix-secure-com-port-redirector-p7194/
Contents
Typical application
Typical wiring of the converter with M-Bus devices, power supply and a computer connection via Ethernet.
LED indication
| Status LEDs | Color | |
|---|---|---|
| Power | connected power supply indication | blue |
| Transmit | indication of data broadcasting on the M-Bus line | green |
| Receive/Overload | indication of data reception and M-Bus line overload. | yellow |
| – indication of data reception on the M-Bus line – LED is flashing | ||
| – indication of M-Bus line overload – LED stays on (idle current > 7.5mA) | ||
| Short | indication of short on the M-Bus line – turned on (resistance of the line < 1kΩ) | red |
Connectors on the M-Bus side
| Connector | Type | |
|---|---|---|
| M-Bus | Connector for the M-Bus line. | built-in |
| Power | Connector for power supply. | built-in |
| ∿ | Power supply pole. | |
| ∿ | Power supply pole. | |
| ⏚ | Earth ground. | |
Connectors on the Ethernet side
| Connector | Type | |
|---|---|---|
| Ethernet RJ45 | Connector for Ethernet cable connection. | RJ45 |
| Status LEDs | Color | |
| Link | Network connection state. Turns on when a network connection is available. | green |
| Rx/Tx | Network communication activity. Flashes only during data transfer. | yellow |
