Wait for the process
Start the pump only after a 200 ms hold.
Turn PumpOn ON only after Start has been held for 200 ms, so a quick tap does nothing. Use an , which waits a set time before switching ON. When Start is released, PumpOn turns OFF and the timer goes back to zero.
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Pump starts after exactly 200 ms
Test 1 of 3StartStart requestONPumpOnPump commandON- Level
- Foundation
- Time
- About 8 min
- Reward
- +100 XP
- Rig
- 3D pump skid
- Siemens editors
- SCL, LAD
- Rockwell editors
- Structured Text, Ladder
- Course stage
- 4. Wait, then act
What the tests check
- PumpOn stays OFF while Start has been held for less than 200 ms.
- PumpOn turns ON once Start has been held for 200 ms.
- Releasing Start resets the timer. The next press waits the full 200 ms again.
- Try it Use the buttons below the model and watch the rig respond.
- Test solution Every check runs on your code in one press.
- Replay If one fails, step through it one scan at a time to see why.
Where you’d see this on site
At a factory wash station, the operator must hold Start for a moment before the pump runs. A quick tap should do nothing.
If every accidental tap starts the pump, water sprays into the wash area. The delay tells a deliberate hold from a brush of the button.
In a block of flats, a basement tank holds water from the mains. Two pumps push it up to the taps above. One runs while the other waits as a spare. A low-water switch stops the pumps before the tank runs dry.
- Street mainsWater enters the building
- Storage tankHolds a supply for the pumps
- Water pumpsPush water to the floors aboveYou are here
- Taps upstairsResidents use the water they need
On a real site: places, parts and safety
- Block of flats — pushing water up to the top floors
- Brewery — sending hot water to a brewing tank
- Water-treatment works — moving water between filter tanks
- Office building — pumping water round the heating pipes
A low-water switch can take away permission to run. The pump must stop before it runs dry and damages its seal.
The PLC can say ON even when a pump has failed. Check the measured flow as well as the command.
The Stop input in these exercises is not an emergency stop. Real machines also need guards, emergency stops and a safe way to cut the power.
The sizes, timings and cutaways are teaching choices, not a drawing of any one real installation.
Next in the course
- Count the arrivalsCount each bottle once. Stop at three.Foundation · 8 min · +100 XP
- Count with a one-shotOne bottle covers the sensor for many scans. Count it once.Applied · 18 min · +250 XP
- Count bottles as they leaveCount each bottle as it clears the sensor, not as it arrives.Applied · 10 min · +150 XP
- It never reaches threeSomething keeps clearing the count. Find it.Applied · 12 min · +200 XP