Example: Implement Position Control
A full worked setup, two proximity sensors and two end switches running an implement's raise and lower
Example: Implement Position Control
Two relays raise and lower an implement. Two 12V proximity sensors on a ground-following wheel report "too low" and "too high". Two end switches bound the travel.
This example uses two tiles on purpose. One arms the position control, the other keeps the limits armed the whole time.
Wiring
| Input | Sensor | Wiring |
|---|---|---|
| IN1 | Proximity, "too low" | Standard, active when the sensor sees the target |
| IN2 | Proximity, "too high" | Standard |
| IN3 | End switch, raise limit | Normally closed, with INVERT set |
| IN4 | End switch, lower limit | Normally closed, with INVERT set |
Outputs: CH1 raises, CH2 lowers.
Setup
| Input | Mode | Outputs | Timings |
|---|---|---|---|
| IN1 | FOLLOW | CH1 | Debounce 50 ms, on delay 0.3 s, off delay 0.2 s, min on 0.2 s, max on 10 s |
| IN2 | FOLLOW | CH2 | The same |
| IN3 | BLOCK | CH1 | Defaults |
| IN4 | BLOCK | CH2 | Defaults |
| Tile | Name | Inputs | INTERLOCK |
|---|---|---|---|
| 1 | POS CTRL | IN1, IN2 | On |
| 2 | LIMITS | IN3, IN4 | Off |
How It Runs
The operator taps POS CTRL and the implement follows the ground.
- The on delay ignores bumps, so the implement does not twitch every time the wheel drops into a hollow.
- The off delay stops hunting when a sensor sits right on its switching distance.
- Min on keeps the relays from clicking themselves to death on short corrections.
- Max on catches a sensor that fails stuck-on, and turns the tile amber when it trips.
- INTERLOCK covers the case where both proximity sensors read active at once. Nothing moves until they disagree again, then the surviving demand takes over.
Grab the joystick and POS CTRL drops out instantly, because the joystick overlaps its channels. LIMITS stays armed and keeps bounding the automation. One tap re-arms the position control.
Why the Limits Are a Separate Tile
If the end switches were part of POS CTRL, they would disarm together with it every time the operator took manual control. Keeping them on their own tile means they stay armed while you work by hand, and they only stop automatic movement, never yours.
Wiring Rule Worth Remembering
Wire limit switches normally closed and set INVERT. A broken wire then blocks the automation instead of silently removing the protection.
The reverse is also true and it is the trap. INVERT on a FOLLOW or TOGGLE input means a cut wire reads as "active", which looks to the module like a sensor demanding movement forever. Give those inputs a MAX ON value so something stops them.