Switching Device ROSSMA® IIOT-AMS Modbus

ROSSMA IIOT-AMS MODBUS meter-switch is designed for autonomous polling of industrial instruments/controllers via RS-485 interfaces, with subsequent wireless data transmission. Additionally equipped with three independent inputs for pulse counting or for monitoring state changes on each input (closed/open) and an additional output for powering external devices with 5 V. Features remote configuration and binding capabilities.

Fig. ROSSMA IIOT-AMS MODBUS meter-switch appearance

Technical Specifications

Inputs / Connection Interfaces:

• 1 RS-485 serial interface | for MODBUS modifications
• 3 multifunctional discrete inputs | for MODBUS modifications
• Built-in temperature sensor
• Battery voltage measurement

Electrical Characteristics:

• Supply voltage (external power from AC mains MODBUS): 230 V
• Supply voltage (autonomous power): 3.3 V to 3.6 V
• Power consumption (autonomous): 0.99 W
• Power consumption (external 230 V power): 62.7 W
• Current consumption (autonomous): 0.3 A
• Current consumption (external power): 0.3 A

Operating Characteristics:

• Operating temperature range: -55…+80°C
• Protection degree (general industrial version): IP65 and IP66
• Explosion protection marking: 1Ex e IIC T4 Gb X
  • Where X in marking indicates special conditions: device operating temperature range -55°C..+80°C

LoRaWAN Network Characteristics:

• Device class: LoRaWAN A or B
• Frequency plan: RU868, EU868, IN865, AS923, AU915, KR920, US915, KZ865
• Activation method: ABP or OTAA (configurable), default ABP
• Communication interval: configurable via LoRaWAN network
• Built-in antenna, sensitivity: -138 dBm
• Radio communication range: up to 5 km in dense urban areas; up to 15 km outside populated areas
• Transmitter power: default 25 mW, maximum 100 mW

NB-IoT Network Characteristics:

• Frequency plan: B1/2/3/5/8/12/13/17/18/19/20/25/26/28/66/70
• Communication interval: configurable
• Built-in antenna
• Sensitivity: -138 dBm
• Radio communication range: up to 5 km in dense urban areas; up to 15 km outside populated areas
• Transmitter power: default 25 mW, maximum 100 mW

Housing Options:

• General industrial version: 115×90×50
• Explosion-proof version: 260×160×90, 220×120×90, 80×75×55
• Cable gland types: specified in agreement with customer
• Mounting: DIN rail adapter or mounting loops

Capabilities

• Simultaneous operation of up to 8 devices via RS-485
• External automation device control
• Built-in 220 V power supply
• Built-in non-volatile memory
• Configuration capability
• Batch data transmission

Application Areas

• Data collection and remote control of technological equipment
• Applicable for oil production industry for process control systems
• Control stations for ESP / EODN / SGPS / HGPS / SNU / UNU / UDS (OU)
• Gas separator installations, pumping stations
• Electrochemical protection stations
• Reagent supply/dosing units
• Data collection from instruments with RS-485 interface

LED Indication

ROSSMA IIOT-AMS MODBUS meter-switch has the following indicators:

• ACT - data exchange with sensor or controller via MODBUS protocol
• Lora - transmitting/receiving data via LoRaWAN network
• Err - indicator signals MODBUS protocol exchange error
• PWR - power
• NET - NB-IoT network connection
• Success - successful NB-IoT transmission

ROSSMA IIOT-AMS MODBUS meter-switch has a RESET button for device reset.

Modbus Device Configurator go to

Equipment is registered in the register of the Ministry of Industry and Trade of the Russian Federation as equipment manufactured on the territory of the Russian Federation (Conclusion 48859/11 dated June 11, 2021).

Firmware

Main Microcontroller (MainMCU)

Version: 0.3.5d (01.06.2025) — ⬇️ Download

What's new in v0.3.5d:

• Improved LoRaWAN module for large packet transmission

v0.3.5c (26.05.2025) — Fixed version formatting

v0.3.5b (20.05.2025):

• Improved secondary MCU message handling algorithm
• Improved im880 interaction module
• Improved message formation module

v0.3.5a (20.05.2025):

• Support for new secondary MCU type
• New algorithm for secondary MCU message handling
• New data transfer algorithm between secondary and main MCU

LoRaWAN Communication Module

Version: 0.4.4c (01.06.2025) — ⬇️ Download

What's new in v0.4.4c:

• Improved LoRaWAN module for large packet transmission

v0.4.4b (26.05.2025):

• Improved secondary MCU message handling algorithm
• Improved im880 interaction module
• Improved message formation module

v0.4.4a (20.05.2025) — New data transfer algorithm between primary MCU and communication module

Secondary Microcontroller (SecMCU)

Version: 0.11.1d (09.04.2025) — ⬇️ Download

What's new in v0.11.1d:

• Fixed archive data search that in some cases caused MCU freeze

v0.11.1c (07.04.2025) — Fixed monitoring result processing when registers are missing

v0.11.1b (06.04.2025) — Fixed sending monitoring messages with errors

v0.11.1a (03.04.2025):

• Additional timeout after monitoring trigger
• Improved error message formation algorithm
• Timeout (PERIOD × 60 sec) after 3 consecutive monitoring errors

How to update: Use ST-LINK programmer for flashing via SWD interface.

Additional Information

• Device Installation — installation instructions
• Battery Replacement — battery replacement
• Protocols and Commands — control commands and data formats
• ROSSMA Configurator — device configuration
• Troubleshooting — diagnostics and problem solving

Related Pages

Software:

• ROSSMA Configurator — Modbus profile settings, transmission intervals
• ROSSMA NETS Server — telemetry viewing, device management
• Data Decoder — Modbus payload analysis

Technical Documentation:

• Exchange Protocols — MODBUS device packet format
• LoRaWAN Technology — RU864 frequency plan, device classes
• Quick Start — first network connection

Other Devices:

• ANALOG Single Channel — for 4-20 mA sensors
• PULSE — for pulse sensors
• Device Catalog — all ROSSMA IIoT-AMS models