¶ Tutorial: Your First Project
Build a traffic light controller from scratch - step by step.
¶ What You'll Build
A simple traffic light sequence with:
- 3 steps: Red, Green, Yellow
- Timed transitions between each phase
- Output variables for each light
¶ Step 1: Create the Project
- Open AutomationView
- Press Ctrl+Shift+P and select AutomationView: Create Project
- Name it
traffic-light
You get three files:
traffic-light/
machine.machine # Project configuration
main.seq # Main Sequence diagram
from automation_machine import Sequence, StepType, ActionInstruction
class TrafficLight(Sequence):
def setup(self):
# Define steps
s0 = self.add_step(StepType.INITIAL, name="Red")
s1 = self.add_step(name="Green")
s2 = self.add_step(name="Yellow")
# Timed transitions
self.add_transition(s0, s1, condition="timer_red.Q")
self.add_transition(s1, s2, condition="timer_green.Q")
self.add_transition(s2, s0, condition="timer_yellow.Q")
# Actions - lights ON while step is active
s0.add_action("red_light", "Red light on")
s1.add_action("green_light", "Green light on")
s2.add_action("yellow_light", "Yellow light on")
# Timers - each step has its own duration
s0.add_action("timer_red", "Red phase timer", instruction=ActionInstruction.TON, duration=10000)
s1.add_action("timer_green", "Green phase timer", instruction=ActionInstruction.TON, duration=8000)
s2.add_action("timer_yellow", "Yellow phase timer", instruction=ActionInstruction.TON, duration=3000)
Save the file. The visual editor instantly shows the Sequence diagram.
self.add_step(StepType.INITIAL)creates an initial step - the starting point of your Sequence (shown with a double border in the editor).s0.add_action("red_light", "Red light on")uses the default Non-stored (N) qualifier - the action runs continuously while its step is active and stops when the step deactivates.instruction=ActionInstruction.TONuses the TON (On-delay timer) instruction. The timer starts when the step activates, and its.Qoutput becomes TRUE after the specifiedduration(in milliseconds).
Open main.seq and write the following program. This creates three steps connected by timed transitions, with actions that control the lights.
¶ Step 4: Run the Emulation
The PLC Emulation engine lets you test your program without physical hardware.
- Press F5 to start
- Watch the Sequence Editor:
- Step 0 (Red) activates first - it is the initial step
red_lightturns ON- After 10 seconds, the TON timer fires and the transition to Step 1 (Green) is crossed
- After 8 seconds, the transition to Step 2 (Yellow) fires
- After 3 seconds, the transition back to Step 0 (Red) fires
- The cycle repeats indefinitely
- Press Shift+F5 to stop
Use F10 to single-step through the emulation one scan cycle at a time. This is helpful for understanding exactly when transitions fire and steps change.
¶ Step 5: Observe Variables
Open the Variables panel in the sidebar. You will see real-time values updated by the emulation engine:
red_light:TRUEwhen Step 0 is activegreen_light:TRUEwhen Step 1 is activeyellow_light:TRUEwhen Step 2 is active- Timer elapsed times updating live
You can force variable values during emulation to test edge cases. See Variable Management for details.
¶ What's Next?
Congratulations! You have built and tested your first AutomationView project. Here are some ideas to explore next.
Try extending this project:
- Add a pedestrian button that interrupts the normal sequence
- Add a flashing yellow night mode using the P (Pulse) qualifier
- Use macro steps to group the pedestrian sequence into a sub-program
- Add counters to track how many cycles have completed
- Explore divergences to create alternative paths based on conditions
¶ See Also
- PLC Emulation - Full details on the emulation engine and controls
- Variable Management - Defining and organizing project variables
- Qualifiers Overview - All available action qualifiers
- Steps - Understanding SFC steps in depth
- Transitions - How transitions connect steps
- Smart Completion - Auto-complete support while editing