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Interoperating with Ladder Logic

Cubloc executes BASIC first. To enable Ladder Logic, use the command Set Ladder On.

Set Ladder On            ' If using only BASIC, don't use this statement

To Use Only Ladder Logic

If you do not need to use BASIC, you can program in Ladder Logic alone. But you will need a few lines of BASIC to get started, as shown below:

Const Device = CB280          ' Select device
UsePin 0,In,START             ' Declare pins to use
UsePin 1,Out,RELAY
Alias M0 = MOTORSTATE         ' Set Aliases
Set Ladder On                 ' Start Ladder.

Device model, aliases, and pin I/O mode must be set in BASIC. Ladder Logic must be started in BASIC with the Set Ladder On statement.

Sharing Data

The Cubloc has separate BASIC and Ladder Logic data memory areas.

Ladder Logic data memory can be accessed from BASIC easily by using system variables. Using these system variables, data can be easily read from or written to Ladder Logic data memory.

System Variable
Access Units Ladder Logic Register
_P Bits _P(0) to _P(127) P Register
_M Bits _M(0) to _M(511) M Register
_WP Words _WP(0) to _WP(7) P Register (Word Access)
_WM Words _WM(0) to _WM(31) M Register (Word Access)
_T Words _T(0) to _T(99) T Register (Timer)
_C Words _C(0) to _C(49) C Register (Counter)
_D Words _D(0) to _D(99) D Register (Data)

Registers P and M can be accessed in units of bits, and registers C, T, and D can be accessed in units of words. To access P and M registers in units of words, use _WP and _WD. For example, _WP(0) represents P0 through P15.

The following is an example program :

_D(0) = 1234
_D(1) = 3456
_D(2) = 100
For I = 0 TO 99
    _M(I) = 0
IF _P(3) = 1 Then _M(127) = 1

Accessing BASIC variables from Ladder Logic is not possible, but you can use Ladder interrupts to request a BASIC routine to change a Ladder Logic variable.

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cubloc/interoperating_with_ladder_logic.txt · Last modified: 2017/02/09 14:17 by COMFILE Technology