Skip to main content

Edge Agent Overview

What the Edge Agent is​

The Haltless Edge Agent is a lightweight service you install on your own hardware, on the same network as your machines. It reads data directly from industrial equipment using native protocols, then streams those readings to Haltless over an outbound HTTPS connection.

The agent is designed to run unattended as a background service. Once configured, it collects on a fixed interval, forwards readings to Haltless, and keeps working through network interruptions without losing data.

It speaks four sources out of the box:

  • Modbus TCP , read registers from PLCs, drives, meters, and sensors
  • OPC-UA , read node values from an OPC-UA server
  • CSV files , watch a directory of exported CSV files
  • JSON / JSONL files , watch a directory of exported JSON files

Why use the Edge Agent​

Protocol-native. The agent talks Modbus TCP and OPC-UA directly, the same protocols already built into most modern industrial equipment. There are no proprietary sensors or gateway devices to buy, and it runs on hardware you already have.

Outbound-only, firewall-friendly. The agent only ever makes outbound HTTPS connections to Haltless. Nothing needs to connect into your plant network, so there are no inbound firewall holes to open and your machines never have to be exposed to the internet.

Resilient to outages. Readings are held in memory and sent in batches. If Haltless is temporarily unreachable, the agent writes readings to a crash-safe local buffer on disk and keeps collecting. When connectivity returns, it drains the buffer in order before resuming normal operation, so brief outages don't lose data (bounded by the buffer's configured size cap and retention window).

You stay in control. Data stays on your network until the agent pushes it. You choose the collection frequency, which machines and metrics to read, and how much local buffering to allow.

How it fits into Haltless​

  Your plant network                         Haltless
  ─────────────────────────                  ─────────────────────────
   OPC-UA server ──┐
   Modbus device ──┤
   CSV exports  ───┤        outbound
   JSON exports ───┤         HTTPS
                   ▼      ──────────────►     Ingestion
              Edge Agent                          │
           (collect + buffer)                     ▼
                                          Normalize + anomaly
                                              detection
                                                  │
                                                  ▼
                                            Alerts + dashboards
  1. The agent collects readings from every configured source on each cycle.
  2. It sends them to Haltless as batches over HTTPS, authenticated with an API key.
  3. Haltless normalizes the readings and runs them through anomaly detection.
  4. Anomalies can raise alerts and appear on your dashboards and reports.

Key concepts​

Machine identifier​

Every reading references a machine identifier , a short, stable string you assign when you register a machine in Haltless (for example CNC-001 or PUMP-MAIN-FLOOR2). In the agent configuration, each source is tagged with the machine identifier it belongs to, and that value must match the registered machine exactly. Identifiers are case-sensitive.

Metrics and units​

Each reading carries a metric_name (such as temperature_celsius or spindle_speed_rpm), a numeric value, and a unit (such as celsius or rpm). A unit is always required. An optional raw_tag can carry the original source address or tag name for reference.

Batching​

To stay efficient, the agent accumulates readings and sends them in batches rather than one request per reading. Batch size is configurable, and a single batch can span multiple machines and metrics.

Heartbeat​

The agent checks in with Haltless on a regular heartbeat to confirm connectivity and subscription status. If the subscription is inactive, the agent automatically pauses collection until it is restored, so it never accumulates data that cannot be delivered.

Agent or agentless?​

The Edge Agent is the right choice for most industrial environments, because your machines stay behind your firewall and data is buffered locally during outages.

If you'd rather not run local software, you can send readings straight to the Haltless ingestion API yourself. See Direct ingestion for the agentless approach.

Next steps​