The Index AMI HW3 acts as a communication bridge between the industrial metering system and the AMI Platforms. This guide describes the TCP client-server architecture that supports real-time remote meter reading.
Overview
The Index AMI establishes an intranet with the 4G LTE cellular operator, which in turn connects to the AMI Platforms via a bidirectional TCP client-server architecture. Readings flow from the meter to the AMI Platforms; read requests flow in the opposite direction.
TCP client-server architecture
Communication is organized around two fixed endpoints:
- TCP Client — Index AMI Monitor: Default port 5025. Must not be changed. The Index AMI initiates the connection to the AMI Platforms and publishes meter readings on this port.
- TCP Server — AMI Platforms: Default port 5000. Can be changed by the user according to the AMI Platforms network configuration. The AMI Platforms listen on this port and send read instructions to the Index AMI.
The Index AMI acts as a bridge: it receives instructions from the AMI Platforms (server) and translates them into the RS485/RS232 protocol to query the meter. The meter response returns through the same channel back to the AMI Platforms.
Transport: 4G LTE cellular intranet
Communication between the Index AMI and the AMI Platforms travels over the cellular operator's network. The operator establishes a private intranet connecting both endpoints without exposure to the public internet. This requires a correctly configured APN and, optionally, a WireGuard VPN tunnel for additional security.
Two connectivity models for reporting
The Index AMI can report information to the AMI Platforms under two connectivity models, depending on the available infrastructure:
- Model 1 — VPN over the cellular network: The Index AMI uses a cellular data plan with internet access and establishes an encrypted, end-to-end WireGuard VPN tunnel to the broker. Encryption and routing are managed by Noatec or the customer; it works with any operator whose SIM has internet access.
- Model 2 — Network operator's last-mile solution: The network operator or distributor provides a last-mile solution over its cellular network: a private APN that connects the Index AMI to the AMI Platforms through the operator's private intranet, with no exposure to the public internet. Security and routing are guaranteed by the operator's network, so no additional VPN is required.
Protocol to the meter: RS485 / RS232
The Index AMI communicates with the industrial metering system via RS485 or RS232, using DLMS/COSEM or Modbus RTU standards depending on the meter model. The physical harness connects the meter's serial port to the Index AMI phoenix connector.
Initial configuration via Bluetooth (BLE)
The Index AMI includes a Bluetooth module that allows initial configuration without remote access. From the Index AMI Android app, the TCP connection parameters can be set:
- TCP server IP address and port: AMI Platforms IP and port 5025 (must match the TCP server port on the AMI Platforms).
- Report types: Power On, Power Off and Status — define which events the Index AMI reports to the AMI Platforms.
Compatible systems at the AMI Platforms
The AMI Platforms can be any system capable of acting as a TCP server on the configured port. Typically integrated systems:
- Index AMI Monitor — Noatec desktop application for real-time monitoring
- HES (Head-End System) — meter data acquisition system
- MDMS (Meter Data Management System) — data management and storage
- SCADA / EMS — energy supervision and control platforms
- CIS (Customer Information System) — billing and commercial management
- EAMS — event and alarm management
- CAMS — cybersecurity and access management
Flow summary
- The industrial meter connects to the Index AMI via RS485/RS232.
- The Index AMI establishes 4G LTE connectivity with the cellular operator.
- The operator provides a private intranet to the AMI Platforms.
- The AMI Platforms (TCP server port 5000) send read requests to the Index AMI.
- The Index AMI (TCP client port 5025) queries the meter and returns the reading to the AMI Platforms.
- Initial configuration is done locally via Bluetooth with the Android app.