Logic module

Program your gateway like a PLC — by simply assembling blocks, with no external server or supervisor.

How it works

The logic module turns the Weble gateway into a programmable controller (PLC), right next to the equipment. You build logic circuits in a visual web editor — no programming knowledge required. A circuit reads values from any connected protocol (KNX, BACnet, Modbus, MQTT…), applies conditions, calculations and timing, then triggers actions. Everything runs directly on the gateway: no dedicated PLC, no server, no cloud dependency. There is no fixed limit on the number of circuits or blocks.

Weble logic module diagram: KNX, Modbus, BACnet and schedule inputs processed by logic circuits on the gateway, into KNX, e-mail/SMS and cloud actions

Building an automation

By assembling blocks, from the simplest to the most advanced.

A circuit is assembled from blocks connected by links that carry values and trigger execution. A few families cover most needs:

  • Logic gates (AND, OR, NOT…) — combine several conditions before acting.
  • Calculation & expression blocks — handle numbers and text: (a+b)/c, unit conversions, building a message.
  • Triggers — react to an event (a KNX telegram, a value change) or to a scheduled time.
  • Actuators — write a value, send a message, drive an output.

Both European and American gate notations are supported. Circuits can be imported and exported to reuse them across projects. And for developers, custom JavaScript blocks open full access to the gateway API.

Scheduling & events

Schedule recurring actions with a simple date format or a full CRON expression — for example “every weekday at 7 am”. In parallel, triggers react in real time to field events. The two combine within a single circuit: logic that is both time-based and event-based, with no manual intervention.

Use cases

Four concrete examples of what the logic module makes possible on a real installation.

Threshold control & comfort scenes

A temperature read over KNX or Modbus is compared to a setpoint; depending on the result, the circuit drives heating, blinds or lighting. You can also build scenes — one press triggers a whole sequence (presence, comfort, night) across several devices at once.

Conditional e-mail / SMS alert

The circuit monitors a value or a fault. When a condition is met, an expression block builds the message text (including the value at fault) and an actuator sends it by e-mail or SMS to the on-call team — with no third-party supervisor.

Counter & scheduled task

Increment a counter, accumulate runtime hours, or run a maintenance action every night via CRON. The gateway runs the task on its own, at the set time, and keeps the value even after a reboot.

Multi-protocol logic

Combine KNX, Modbus and BACnet inputs in a single circuit: for example, force a Modbus setpoint only if a KNX presence and a BACnet schedule are both active at the same time. It is the full power of inter-protocol routing, with a layer of decision logic on top.

Try the live demo → Full documentation (wiki) →