Siemens 505-2557 Items Unique to the Simatic 505±2557 Module, Open RTD Status Bits

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3.10Items Unique to the SIMATIC 505±2557 Module

Items unique to the SIMATIC 505±2557 RTD Input Module.

Open RTD Status Bits: WX55

Figure 3-18 Open RTD Status Bits

The bits returned in WX 55 indicate an open RTD for a particular channel.

Floating Inputs

If no RTD is connected to an input channel the value returned to the PLC is unpredictable.

The inputs on the SIMATIC 505±2557 are floating; that is there are no internal pull up or pull down circuits to force the input to either a maximum or minimum temperature value. Unused inputs therefore should be terminated by shorting the V+ and G terminals together.

SIMATIC 505±2557 Installation and Operation Guide

Advanced Function Programming 3-31

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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 European Agency ApprovalsCommunity CE Approval100 Ohm, 10 Ohm, 120 Ohm RTDs, or Millivolt Inputs DescriptionOperating Modes Word Input to the PLC from the Module Scale Units RTD Input to Digital ConversionEffect SignalsOut-of-Range Input Effect of Voltage Input 10 Ohm Copper Input Resolution ResolutionCalculating the I/O Base Power Budget Installing and Configuring the ModuleSelecting 2 and 3 Wire or 4 Wire Operation Installing and Configuring the Module Configuring Selecting Temperature orMillivolt Input Celsius or Selecting DegreesFahrenheit Selecting DataConfiguration Jumper Locations Module Into InsertingBase Copper Wire Table at 25 Degrees Celsius Wiring the Input ConnectorsPress 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 Introduction Advanced Software FunctionsOverview AdvancedConfiguration Setting the ModuleJumper Controller I/O LoggingMemory Input and Output Register Offsets Internal Register StructuresInput Registers Input Channel DataPeak/Valley Hold Input Words Input Flag BitsAveraging Output Data RegistersControl Registers Function Enable BitsInputs Discrete Handshake Inputs Data Identification Bits OutputsData Loading Process Loading Data into the Simatic 505±2557 ModuleSample 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 Overhead for Functions Enabled When UsingTiming Considerations Timing ConstraintsDefault Function Values Default ValuesDefault Function Values for Simatic 505±2557 Additional Information about Each FunctionDegrees Alarm SetpointsCentigrade or Degrees FahrenheitDigital Filtering Peak and Valley AveragingHold Flag Bits Hold ResetPrecedence FunctionTroubleshooting Symptom Probable Cause Corrective Action 10 Troubleshooting Flow Diagram17 I/O Register Quick Reference I/O Register Quick ReferenceOr K Memory Configuration Tables Page Addressing Worksheet 18 Open RTD Status Bits Items Unique to the Simatic 505±2557 ModuleTroubleshooting Table B-1 Specifications SpecificationsSpecifications subject to change without notice Jumper Settings Log Sheet Customer Response Business Reply Mail