Chapter 13

Programming Considerations

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Forcing

13-1

 

 

Extended forcing

13-2

 

 

Using special programming routines

13-10

 

 

Priority scheduling for interrupts and MCPs

13-11

 

 

Defining and programming interrupt routines

13-15

 

 

Forcing

Forcing I/O lets you turn specific input and output bits on or off for testing purposes. Forcing bits on or off or forcing SFC transitions lets you simulate operation or control of a device.

IMPORTANT

Forcing inputs lets you force the bits in the input image file. Forcing output lets you force the actual output module, leaving the output image table file in its original state.

Forces are held by the controller (and not the personal computer). Forces remain even if the personal computer is disconnected

 

 

 

 

When anything is forced on or off, keep personnel away

 

ATTENTION

 

from the machine area. Forcing can cause unexpected

 

 

 

 

 

 

 

 

machine motion that could injure personnel.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Forcing Inputs and Outputs

You can forces bits directly from the ladder editor or the force monitor screens in your programming software. After you configure which bits to force, you must enable forces before the forces take effect.

You can only force live I/O points, which are bits in an input or output word that are physically attached to and configured for your system.

Publication 1785-UM012D-EN-P - July 2005

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Bradley Smoker PLC-5 user manual Programming Considerations, Forcing Inputs and Outputs, 13-11, 13-15