Siemens 505-2557 installation and operation guide Function, Precedence

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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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Contents Simatic Copyright 1998 by Siemens Energy & Automation, Inc Manual Publication History List of Effective Pages Contents Iv Contents List of Figures List of Tables Preface Community CE Agency ApprovalsEuropean ApprovalDescription 100 Ohm, 10 Ohm, 120 Ohm RTDs, or Millivolt InputsOperating Modes Word Input to the PLC from the Module RTD Input to Digital Conversion Scale UnitsSignals EffectOut-of-Range Input Effect of Voltage Input 10 Ohm Copper Resolution Input ResolutionInstalling and Configuring the Module Calculating the I/O Base Power BudgetSelecting 2 and 3 Wire or 4 Wire Operation Installing and Configuring the Module Configuring Temperature or SelectingMillivolt Input Fahrenheit Selecting DegreesCelsius or Selecting DataConfiguration Jumper Locations Inserting Module IntoBase Wiring the Input Connectors Copper Wire Table at 25 Degrees CelsiusPress In Wiring Connector Wiring Diagram for 2, 3, or 4 Wire RTD Wiring Diagram for Millivolt Measurements Cable Grounding Example I/O Configuration Chart Advanced Function Programming Overview Advanced Software FunctionsIntroduction AdvancedSetting the Module ConfigurationJumper Logging Controller I/OMemory Input Registers Internal Register StructuresInput and Output Register Offsets Input Channel DataInput Flag Bits Peak/Valley Hold Input WordsOutput Data Registers AveragingFunction Enable Bits Control RegistersInputs Discrete Handshake Inputs Outputs Data Identification BitsLoading Data into the Simatic 505±2557 Module Data Loading ProcessSample Low and High Alarm Setpoints Identifying the Data Being Transferred 11 Enabling the Functions Loaded Loading Programs into the I/O Module 13 Startup Relay Ladder Logic Page Timing Considerations When UsingTiming Overhead for Functions Enabled Timing ConstraintsDefault Function Values for Simatic 505±2557 Default ValuesDefault Function Values Additional Information about Each FunctionCentigrade or Alarm SetpointsDegrees Degrees FahrenheitDigital Filtering Averaging Peak and ValleyHold Hold Reset Flag BitsFunction PrecedenceTroubleshooting 10 Troubleshooting Flow Diagram Symptom Probable Cause Corrective ActionI/O Register Quick Reference 17 I/O Register Quick ReferenceOr K Memory Configuration Tables Page Addressing Worksheet Items Unique to the Simatic 505±2557 Module 18 Open RTD Status BitsTroubleshooting Specifications Table B-1 SpecificationsSpecifications subject to change without notice Jumper Settings Log Sheet Customer Response Business Reply Mail