Black Box GEH-6510 manual About DDE, About NetDDE

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About DDE

DDE is the acronym for Dynamic Data Exchange, a communications protocol that allows independently developed Microsoft Windows 2000 SP2 programs to share data and instructions with each other.

DDE implements a client-serverrelationship between two concurrently running programs. The server application provides data and accepts requests from any other applications interested in its data. The applications requesting the data are called clients.

Requests for data can be of two types: one-time requests or permanent data links. With one-time requests, the client program requests a “snapshot” of the desired data from the server application. An example of a one-time request is a program such as Excel running a report-generating macro. The macro opens a temporary link to another application, requests specific data, closes the link, and uses the data to generate the report.

Permanent data links are called hot links. When a client application sets up a hot link to another application, it requests the server application to advise the client whenever a specific item’s data value changes. Hot links remain active until either the client or server program terminates the link. Hot links are an efficient means of exchanging data because, once the link has been established, no communication occurs until the specified data value changes.

The DDE protocol specification includes standardized formats for messages to be exchanged between DDE-compliant applications (such as Microsoft Excel).

About NetDDE

NetDDE for Windows 2000 SP2 is an extension to DDE. With NetDDE, client applications do not have to be running on the same PC as the DDE Server; a client application on one PC may request data from a DDE Server operating on another PC. Its capabilities include communication over local-area networks and through serial ports.

Two or more networked IBM-compatible PCs running Windows 2000 SP2 are required to run NetDDE. The version of NetDDE which is supplied with Windows 2000 SP2 is the recommended version; other versions of NetDDE are not recommended for use with PMCS.

2 • Chapter One - Introduction

DDE Server User’s Guide

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Contents Power Leader TM DMMS425 Back to Main Menu Contents Glossary of Terms This page left blank intentionally Welcome Chapter One IntroductionAbout NetDDE About DDEServer with OPC Interfaces InstallationAbout the Pmcs DDE Server EI User’s onlyChapter One Introduction DDE Server User’s Guide Running Pmcs DDE Server as an NT Service About Pmcs Chapter Two OverviewChapter Two Overview DDE Server User’s Guide Sample register map DevicesWhat’s Next NetworksPmcs DDE Server Client ApplicationsIntroduction First-Time ConfigurationDevice Configuration Chapter Three Getting StartedWhat’s on the DDE Server Screen? Launching the ProgramMenu Conventions Menu BarConfiguring Communication ports EPM 7700 Xpress Card or Xplex 1620 Max Server Users Ethernet Users OnlyChapter Three Getting Started DDE Server User’s Guide Modbus TCP/IP Server Users Chapter Three Getting Started DDE Server User’s Guide Configuring the Devices Device Name Topic Com Port Starting the ServerDisplaying I/O Traffic DDE Server User’s Guide Chapter Three Getting Started NetDDE Setup Overview Automatic NetDDE Setup VNDDE.EXEUtility VNDDE.EXE Error Messages Tips on using VNDDE.EXEResults Additional Help Manual NetDDE SetupTrouble-Shooting VNDDE.EXE VNDDE.EXE FAQ’sChapter Three Getting Started DDE Server User’s Guide DDE Server User’s Guide Chapter Three Getting Started Chapter Three Getting Started DDE Server User’s Guide This page left blank intentionally System Menu Chapter Four Menus and ToolbarsRun Server MenuStop Exit View MenuSuspend Protocol/Resume Protocol Print I/O TrafficDisplay Traffic DisplayColor Add Device BackgroundDelete Clear DisplayRegister groups for display Port Statistics Configure MenuConfiguration Save Display To FilePorts Modbus or EI ConfigureDDE Server User’s Guide Chapter Four Menus and Toolbars Ethernet Gateway Users Ports Ethernet onlyEPM 7700 Xpress Card or Xplex 1620 Max Server Users Chapter Four Menus and Toolbars DDE Server User’s Guide Modbus TCP/IP Server Users Chapter Four Menus and Toolbars DDE Server User’s Guide Device Info AddChapter Four Menus and Toolbars DDE Server User’s Guide Device Type Information ModifyDelete Activate checkboxGeneric Comm Interface DDE Server User’s Guide Chapter Four Menus and Toolbars Active Links Reports MenuToolbar Help MenuTrouble-Shooting the Pmcs DDE Server Chapter Five TroubleshootingWWLogger Communications Client to Server Communications Server to Device NetDDE Trouble-Shooting Trouble-Shooting Flowchart Error Messages Trouble-Shooting ChartCServerAppOnDeleteDev Invalid toolkit index Device device name Active Failed to delete itemlogical device handle, Protocol Handle No Write to Individual Discrete Bits Device type device type name is not a valid type for topic This page left blank intentionally Device Type Information Adding Generic Devices Chapter Six Advanced OptionsAdd Default Type Function Codes Register Map Type Code Type of Register Supported Function Codes Use Adding a Register GroupDDE Server User’s Guide Chapter Six Advanced Options Invalid Register Blocks Modifying a Register Group Modifying an Invalid Register BlockDeleting an Invalid Register Block Deleting a Register GroupImporting or Exporting a Register Group MnemonicsImporting or Exporting Mnemonics Adding a MnemonicModifying a Mnemonic Deleting a MnemonicValid Data Time-out Protocol Timer TickOptimizing Server Performance Server Operational ParametersCommunication Time-out Pmcs DDE Server .ini FileSlow Poll Count TimeDownLoad Period Maximum Query RetriesDead Device Scan Interval SleepTime For ExceptionUIHide ExitDisableData-Addressing Conventions Appendix a Register Addressing ConventionsData Types Standard Data OrganizationExamples Special Naming ConventionsLong Words and Special Numbers XnnnnDL-B Individual Bits In RegistersRegister Array Format This page left blank intentionally Terms You Should Know Glossary of TermsGlossary of Terms DDE Server User’s Guide Index GE Industrial Systems