Cubloc executes BASIC first. To enable Ladder Logic, use the command Set Ladder On. After this command is executed, Ladder Logic will begin running and perform ladder scans every 10 milliseconds.

If the Set Ladder On command is not used, Ladder Logic will not run and no ladder scans will be performed

Set Ladder On

If only using Ladder Logic a minimal amount of BASIC code is required. The BASIC code must contain, at a minimum, a device declaration, the Set Ladder On command, and a Do…Loop to keep the program executing. Port declarations, and aliases must also be declared in BASIC.

The following example illustrates such a program.

Const Device = CB280     'Device Declaration
 
UsePin 0,In,START        'Port Declaration
UsePin 1,In,RESETKEY
UsePin 2,In,BKEY
UsePin 3,Out,MOTOR
 
Alias M0=RELAYSTATE      'Aliases
Alias M1=MAINSTATE
 
Set Ladder On            'Start Ladder
 
Do
Loop                     'BASIC program will run in infinite loop.

Contact A is “Normally Open” and closes when a signal is received. On the other hand, Contact B is “Normally Closed” and opens when a signal is received.

Input/Output registers are the most basic symbols among the registers in Ladder Logic.

Function include timers, counters, and other mathematical operation registers.

Internal registers (M) only operate within the program. Unless connected to an actual external port, they are only used internally. M registers can be used as input or output symbols.

Cubloc supports P registers from P0 to P127. P registers are directly connected to I/O ports one to one. However, most models of Cubloc have less than 128 I/O ports. Those P registers not connected to an I/O port can be used as internal registers (M registers).

Go CUBLOC Ladder Logic home