xLadder user manual-V2.0.0.6

move,because there is no need to worry about addressing conflicts.

interrupt routine

You can write an interrupt routine to handle some predefined interrupt events:The

interrupt routine is not called by the main program;When the interrupt event occurs,

it is called by the PLC operating system.Interrupt routine is best to use local variables.

You can use a local variable table to ensure that your interrupt routine uses only

temporary memory.

5.5 How to enter the ladder logic program

5.5.1 How to build a new project

, Or click on the file drop - down menu Icon , Create a new project.

Click

Open an existing project

Click the “ file ” icon, select “ open ” or “ open the PWM file ” .

5.5.2 Ladder logic element and its working principle

Ladder logic (LAD) is a graphical language which is similar to the electrical relay

diagram.When you write a program in LAD, you use graphical components and

arrange them into a logical network.The following component types are available for

use when you build a program:

contact

the switch which power supply can pass through.When the normally

open contact logic is 1 and the normally closed contact logic is 0, the power supply

can pass through these contacts.

coil

The coil represents the output.

Block

Each block represents a function.

The network is composed of the above elements.The power supply from the left side

of the power rod flows through the closed contact to charge the coil or the block.

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