Ten minutes. That is how long it takes to write, download and run your first xLogic program — even if you have never touched FBD before. The tools are free, the wiring is three screws, and the whole workflow fits on a desk.
This tutorial uses xLogicSoft, the free FBD programming software for SR and PR series controllers. By the end you will have a working start/stop circuit with a delay timer running on real hardware.
What You Need
- A xLogic controller — an SR-12AC-R or PR-12AC-R-N works for this example
- The free xLogicSoft software for Windows (XP, 7, 8, 10 — it even runs on modest office PCs)
- A programming cable: USB or RS232 , both optically isolated
- 24V or mains power for the controller (match the model you bought)
Step 1: Create a Project and Pick the CPU
Open xLogicSoft, click New project , and select your exact model from the device list. The software then shows only the I/O and function blocks your CPU actually supports — you cannot accidentally program a block the hardware does not have.
Give the project a name (the software uses it for the program title shown on the LCD) and save it.
Step 2: Add Your First Block
Every program is a circuit of function blocks wired like relays: signal on the left, action on the right. Drag an on-delay timer block onto the canvas. Wire input I1 to the timer start, and the timer output to relay output Q1.
That single network now does what a hardware timing relay did — with three advantages: the delay is adjustable in seconds from the keypad, the program is readable on the LCD, and you can change the timing without touching a screwdriver.
Step 3: Set Parameters and Simulate
Double-click the timer block to set the delay (try 5 seconds). Before touching the PLC, use the built-in simulator — click the play icon and toggle the inputs with your mouse. If Q1 switches on five seconds after I1, the logic is correct.
Simulation catches most wiring mistakes before they cost a blown fuse.
Step 4: Download to the PLC
Connect the programming cable (see the download tutorial for the three connection options), pick the COM port in the communication settings, and click Download . The controller stops, receives the program, and restarts in RUN mode.
Step 5: Test on Real Inputs
Apply a signal to I1 (a button or a jumper wire) and watch Q1. The relay should close after the programmed delay. Switch to the LCD screen and you can watch the same circuit live on the display — inputs, timer value and output state, updated in real time.
That is the whole loop: build, simulate, download, verify. Most people repeat it fifty times before they need a manual.
What to Learn Next
Your next three Tutorials , in order: Modbus communication setup , program download via USB, RS232 and Ethernet , and the FAQ .html"> FAQ when something unexpected happens.
