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Gateway V4 + Modbus

Wireless M-Bus Gateway V4 with the Modbus (ASCII / RTU) add-on.

Wireless M-Bus Gateway V4 (Battery)

Description​

Gateway for remote reading of Modbus values via NB-IoT, LTE-M mobile radio or LoRaWAN to the Internet. Suitable for indoor and weather-protected outdoor installation.

Features​

All Gateway V4 Series platform features plus:

Accessories

The SP13 connector ships with open cable ends. Use the IP68 Inline Cable Connector (4-pin) to connect to an existing cable quickly and without tools.

Product Components
Firmware
app-nrf91-origin · Firmware updates
Housing
LoCube — 122 × 82 × 55 mm
Power supply
Battery 38 Ah (Li-SOCl₂, 3.6 V) · External 12 V DC or 230 V AC available
Optional accessories
External antenna (SMA) · IP68 encapsulation · LoCube wall mounting kit · Pole mounting kit

Product Identification​

  • Name: Wireless M-Bus Gateway V4 Modbus
  • Type: LOB-GW4-MODBUS
  • MPN / Ordering code: 1200526

Accessories​

AccessoryNotes
LoCube Wall MountOptional — wall or horizontal pipe
LoCube Mast MountMetal bracket for vertical pole / mast mounting
USB Config AdapterFor local configuration, diagnostics, and firmware updates
IP68 Inline Cable Connector (4-pin)For connecting open SP13 cable ends

LED Signal Patterns​

The device uses the standard V4 LED signal patterns. See LED Signal Patterns for the full reference.

Battery Lifetime Estimator​

info

Please contact our sales team.

Configuration​

The device is shipped with default configuration parameters. Local changes can be made via the config port using the USB Config Adapter and the Lobaro Config Tool.

For step-by-step instructions, see the Configuration Methods guides:

tip

Custom factory configuration is available on request — devices can be pre-configured at production for your specific deployment. Contact sales@lobaro.de when ordering.

Firmware Updates​

The latest firmware can be found here:

note

A remote firmware update over LoRaWAN is currently not possible.

Configuration Parameters​

This product runs the app-nrf91-origin firmware. To avoid duplication, the parameters are documented centrally with the firmware component and are not repeated here:

note

The product-specific Modbus tooling and limits below complement the parameter reference above.

Modbus Config Generator​

note

The Modbus request syntax for modbusCmdConf complies with the Modbus specification, except that the 16-bit CRC at the end is omitted.

More Info: Modbus Request Syntax.

Bus Configuration

Modbus RTU
8 bits
None
1 bit

Commands

Server AddressFunctionAddress# 16-Bit Register
0x
03 Read Holding Registers
0x
0x

Maximum number of Modbus responses​

To cache the Modbus responses 4096 byte are reserved in the internal RAM. The memory consumption can be calculated with the Modbus Config Generator. This memory consumption multiplied by the accumulation factor addonAccumulate must not exceed 4096 byte.

When using LoRaWAN a single response must not exceed the maximum payload size loraPLMax.

Up to 4096 bytes are reserved in internal RAM to buffer Modbus responses. The required buffer size can be calculated using the Modbus Config Generator. This calculated size multiplied by the accumulation factor addonAccumulate must not exceed 4096 bytes, otherwise the configuration is considered invalid.

note

The following information applies to the current firmware version (e.g. 0.10.6 and potentially previous releases).

Important: Even if the calculated buffer size is below 4096 bytes, this does not necessarily mean that all buffered Modbus responses will be transmitted within a single uplink message. The effective practical limit for a single uplink (e.g. via LTE/CoAP) is currently approximately 2000 bytes per uplink. If the accumulated uplink payload exceeds this limit, only a subset of the buffered responses is transmitted—typically the most recent measurements—while the remaining responses stay in the cache or are discarded until a subsequent uplink occurs.

Recommendations to avoid partial transmissions:

  • Reduce the number of Modbus requests per cycle

  • Reduce the number of registers per request

  • Adjust the accumulation factor addonAccumulate

  • Configure multiple smaller uplinks instead of a single large uplink

Plausibility checks

When powered up the gateway checks the parameters for plausibility. If invalid parameters or parameter combinations are detected the configuration is not accepted and must be fixed.

Cellular uplink uses CoAP (with the Lobaro IoT Platform) or MQTT for third-party integration. The protocol details are documented centrally with the firmware:

The CoAP implementation details are not publicly disclosed and are intended for use exclusively with the Lobaro IoT Platform. If MQTT is not an option, please contact Lobaro directly.

Wireless M-BUS Parser​

A production-ready parser (including split telegram reassembly where applicable, AES-128 decryption for encrypted wM-Bus telegrams, and OMS-compliant data interpretation) is implemented within the Lobaro Platform.

Customers using the Lobaro Platform can utilize this parser directly as part of the platform processing pipeline.

If you are operating a Lobaro Gateway without using the Lobaro Platform, we can provide restricted platform access upon request. This allows you to inspect the parser behavior and use it as a technical reference for your own backend implementation.

Please contact our support team if you require access or further integration details.

Declaration of Conformity​

PDF DownloadDownload CE declaration of conformity
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