ST Logic Blocks

Composite Composer Instances

A standalone block is a template. To make it control a real machine, you instantiate it in a composite and assign its references — equipment, globals and timers — to concrete hardware.

Add an instance

Open the Composite Composer, select a composite, and go to its Logic Blocks page. Click + Add, name the instance, and double-click the Template cell to pick your block (e.g. LineControl).

What you assign

StateTick reads the block's body and lists every reference it uses as a row to bind. The Status reads Configure until they are all assigned:

A composite Logic Blocks instance named Line1 using the LineControl template, expanded to show an equipment ref Motor (IMotor) and four global refs, each with a bind arrow and a Configure status — Instance `Line1`: an equipment ref (`Motor / IMotor`) and four global refs, each awaiting a binding.

There are four kinds of binding — parameters, equipment refs, global refs and timer refs. Expand the instance and assign each one below; the Status turns green once they all resolve.

Assign parameters

Each of the block's parameters is listed under Parameters. Double-click one to open the binding advisor — a list of the variables it can bind to, filtered to the parameter's type: a global, an equipment interface signal, or a timer property. Pick one to drive that parameter.

The parameter binding advisor listing the variables a Bool parameter can bind to: global variables and equipment interface signals — Double-click a parameter → choose the variable that drives it (type-filtered).

Assign equipment

Step 1 — place the device. On the composite's Equipment page, click + Single, pick the template (Motor), and name the instance (e.g. Conveyor1).

The composite Equipment page showing one instance named Conveyor1 of template Motor — A concrete `Conveyor1` instance of the `Motor` template, placed on the composite.

Step 2 — bind the ref. Back on the Logic Blocks page, double-click the equipment ref's value. Pick the instance to bind it to:

The Select Equipment Instance dialog listing Conveyor1, with Cancel and Select buttons — Double-click the equipment ref → choose `Conveyor1`.

The ref now shows the bound instance:

The Line1 instance with its Motor (IMotor) equipment ref bound to Conveyor1, and the four global refs listed below — `Motor (IMotor)` is now bound to `Conveyor1`. The same template can drive a different motor in another composite.

Assign globals

Global refs are matched to your project globals by name automatically — Global.PartCount in the body binds to the PartCount global with nothing to do. They are listed so you can confirm them, or double-click to point one at a different global.

Assign timers

If the block uses timers, each timer name appears as a timer ref. Double-click it to bind to a timer defined on the composite's Timers page — that is where the placeholder name from the body resolves to a real timer.

Assign them all → green

Once every reference is assigned, the instance Status turns green and the block is live. That is the payoff of ST blocks: author the control logic once, then drive many machines by re-assigning references — no copy‑paste, no drift.

See further — run a block from a state. A logic-block instance can be executed from a machine state as a logic block action — Logic.Execute('LineControl'). The state references the block by name and binds to a configured instance in the composite. See States → Logic Block Actions.

Try it in StateTick

Write your control logic once as an ST block, validate it live, then reuse it across every machine in your factory.

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