Rockwell-automation Logix5000 Controllers Controller Information and S Manual de usuario descargar pdf (Pagina 53)

Chapter 5

Access status information

The controller supports status keywords you can use in your logic to monitor

specific events.

• The status keywords are not case sensitive.

• Because the status flags can change quickly, the Logix Designer application

does not display the status of the flags. For example, even when a status flag

is set, an instruction that references that flag is not highlighted.

• You cannot define a tag alias to a keyword.

The following table lists the available key words.

To determine if Use

The value you are storing cannot fit into the destination because it is either:

• Greater than the maximum value for the destination.

• Less than the minimum value for the destination.

Important: Each time S:V goes from cleared to set, it generates a minor fault (type 4, code 4).

S:V

The instruction’s destination value is 0. S:Z

The instruction’s destination value is negative. S:N

An arithmetic operation causes a carry or borrow that tries to use bits that are outside the data type.

For example:

• Adding 3 + 9 causes a carry of 1.

• Subtracting 25 - 18 causes a borrow of 10.

S:C

This is the first, normal scan of the routines in the current program. S:FS

At least one minor fault has been generated.

• The controller sets this bit when a minor fault occurs due to program execution.

• The controller does not set this bit for minor faults that are not related to program execution, such as

battery low.

S:MINOR

Introduction

Rockwell Automation Publication 1756-PM015F-EN-P – October 2014 53

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Rockwell-automation Logix5000 Controllers Controller Information and S Manual de usuario Pagina 53