FBD logic for LOGO! that survives the handover
We program Siemens LOGO! in Function Block Diagram — proven patterns, simulated before a single wire is live, and a versioned file the next electrician can actually read.
How the program gets built
Map the I/O
List every input, output and timing condition before opening Soft Comfort — the FBD sketch comes first, the software second.
Reuse block patterns
Staircase timer, latching relay, edge trigger, weekly clock — proven function blocks, not logic built from scratch each time.
Simulate the logic
Run the FBD in LOGO! Soft Comfort's built-in simulator against real-world scenarios before any output touches a contactor.
Version and document
Hand over a versioned program file with revision notes, so the next person who opens it isn't guessing.
What we build with
Reusable function blocks
Custom User Defined Functions turn a proven sub-circuit into a block you drop in again, not rebuild.
Staircase & latching
Timed lighting and hold-on circuits built from standard function blocks, not workarounds.
Edge-trigger detection
Rising- and falling-edge blocks for one-shot actions from a single button press.
Weekly time clocks
Schedule-driven logic for lighting, pumps or ventilation across the week.
UDF libraries
Recurring logic packaged as reusable blocks across projects, not copy-pasted.
Simulate before commissioning
Every program is tested in Soft Comfort's simulator against real input sequences first.
What's included
Every FBD program we deliver follows the same discipline, regardless of size.
- FBD program built to your I/O list
- Simulation run-through before commissioning
- Versioned program file with revision notes
- Staircase, latch, edge-trigger and clock blocks reused where they fit
- Handover documentation for future changes
Frequently asked questions
What's the difference between FBD and ladder logic on LOGO!?
Both are supported programming views in LOGO! Soft Comfort. FBD represents logic as connected function blocks rather than rungs — it tends to read more clearly once timers, latches and UDFs are involved.
Can a UDF built for one project be reused on another?
Yes — a User Defined Function is a self-contained block. Once it's built and tested, it can be dropped into a new program without rebuilding the logic inside it.
Why simulate before wiring anything?
LOGO! Soft Comfort's simulator lets us run the exact input sequences a customer will trigger — button presses, sensor edges, weekly schedule changes — before an output ever reaches a contactor.
Do we get a copy of the program file?
Yes — a versioned program file is part of the handover, so a future electrician or integrator can open it, see the revision history, and understand the logic without starting over.
Can LOGO! logic talk to other systems?
Newer LOGO! 8 generations support Ethernet and Modbus TCP with a built-in web server, so FBD logic can expose or receive values from other equipment on the network.
Need FBD logic built for a LOGO! project?
Send us the I/O list and the behaviour you need — we'll come back with a function-block plan before touching Soft Comfort.