Boolean (Contacts and Coils)

Contacts       

A contact represents an action or condition. You can link it to any of the following bit operands:

• Memory Bit

• System Bit

• Network System Bit

• Network System Input

• Inputs

• Output

• Timer

Each contact condition in a net is loaded into the bit accumulator and evaluated to determine the coil (output or expression) condition. There are 4 types of contacts:

• Direct Contact

• Inverted Contact

• Positive Transition Contact (Rise or One Shot)

• Negative Transition Contact (Fall)

Contacts can be connected in series and in parallel on a Ladder net.

Coils      

A Coil represents a result or expression of an action. A coil turns ON when the preceding net conditions are ON, allowing power flow to reach the coil from the net.  If the preceding net conditions are OFF, a coil turns OFF. You can link it to any of the following bit operands:

• Memory Bit

• System Bit

• Output

• Timer

Each contact condition is evaluated in a net to determine the coil (result or expression) condition. Coil types include:

• Direct Coil

• Inverted Coil

• Set Coil

• Reset Coil

• Toggle Coil

 

Note ♦

Do not energize a coil more than once in a program.