Local project›Program blocks›Motor Start/Stop Browser simulation
Program editor / LAD

Motor Start/Stop

STOP20 ms scan
0 scans · 0 ms
Project explorer
Local PLCBrowser simulation · BOOL
Program blocks 8
Exercise library
Local simulationNo controller connected
Task / brief

Goal

MotorRun stays on after Start is released (self-latch), and turns off when Stop is pressed. Pressing Start and Stop together must leave the motor off.

Inputs / outputs

NO physical button: released = 0
NC physical button: released = 1

Hints

Browse exercises

Main [LAD]Modified

Ladder diagram

LAD100%
Network 1
Stop (normal)Stop (normal)%I0.1StartStart%I0.0Stop (normal)Stop (normal)%I0.1Motor RunMotor Run%Q0.0Motor RunMotor Run%Q0.0
Properties coil · 2 paths
Contacts & branches
Path 1
1
2
Path 2
1
2
Output instruction
Q 0
1 networks · 3 tagsSelect a symbol to edit its properties
PLC tags / I/O table (3/64)

%I Input · %Q Output · %M Internal bit / byte.bit (0–7)

Address naming rules
AreaMeaningExample
%IInput%I0.0, %I0.1
%QOutput%Q0.0, %Q1.0
%MInternal bit%M0.0, %M0.1
  • Format: %areaByte.bit. Bytes: 0–65535; bits: 0–7. After %I0.7 comes %I1.0, not %I0.8.
  • Enter I1.2 or i1.2 to normalize to %I1.2. Addresses must match the direction and be unique.
  • Symbol names appear above ladder elements; addresses appear below. All contacts bound to a variable share its address.
  • These BOOL addresses are for simulation. The byte limit does not describe every physical CPU.
SymbolAddressDirectionTypeInitialLiveComment
StartPressedBOOL0
StopOKBOOL1
MotorRunBOOL0

Addresses are saved with the project. Existing tags keep their addresses when another tag is deleted. Exercise IDs keep their physical role.

Program valid
Unsaved changes
Simulation / live I/O

Device feedback

Stopped
STOPPED

Variable table

3
NameAddressValueControl
Start%I0.00
Stop (normal)%I0.11
Motor Run%Q0.00
Addresses are virtual teaching tags.
Diagnostics / verification5 cases

Test 1 of 5

Entire suite · isolated engines · results clear on edit

Test 1: Start then release: motor keeps running

Click Run test to evaluate the entire suite.