Additional Information about Each Function (continued)

Overrange/Underrange flags The overrange (WX52) and underrange (WX53) flag bits are set any time the analog-to-digital converter (ADC) saturates and cannot produce any higher value for positive inputs or lower value for negative inputs.

NOTE: A zero input value is a reasonable input level of signal. It is not uncommon for the input to go below zero and the sign bit to change. The ADC will function below a value of zero until saturation.

Advanced

When using more than one of the advanced functions, it is necessary to

Function

understand the order in which these functions are performed in the

Precedence

SIMATIC 505±2557 hardware. The order of precedence for these functions

 

is as follows:

 

1.

Scaling for low and high engineering units

 

2.

Filtering

 

3.

Alarm processing

 

4.

Peak and Valley hold measurements

 

5.

Averaging

3-24 Advanced Function Programming

SIMATIC 505±2557 Installation and Operation Guide

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Siemens 505-2557 installation and operation guide Function, Precedence