It is best to keep the length of stripped cable leads

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It is best to keep the length of stripped cable leads as short as possible to minimize the length of unshieldedconductors exposed to the noisy environment.Connections can be made directly to the module terminals, or via an intermediate terminal block. Thediagrams in this section show wiring for various types of analog input and analog output installations.2.6.4.10.1Shielding for Analog Input ModulesGenerally, the shield for analog input cables should be grounded at the analog source. However, groundconnections for each channel, labeled COM and GND, can be used to connect shields at the analog inputmodule if appropriate. The COM terminals of the analog input module connect to the analog circuitcommon in the module. The GND terminals connect to the backplane (frame ground). Shields may beconnected to either COM or GND. This section shows four shield grounding examples for analog inputmodules.
PACSystems* RX3i System ManualSection 3GFK-2314TSept. 2019Installation55Analog Input Shield Grounding with aTerminal StripFor an unbalanced source, the ground shield should be connected to the source common or ground at thesource end. If all source inputs to the module come from the same location and are referenced to the samecommon, all shield grounds should be connected to the same ground point. If there is an additional terminalstrip between the analog input module and the field devices (analog sources), use the method displayed inthe following figure to continue each cable shield using a terminal on the terminal strip. Each cable is onlygrounded at one end - the end closer to the field devices (analog sources). Shield connections are shown inred (bold) in Figure 37.AnalogSourceConnectionto FrameGroundAnalog InputModuleEnclosureTerminalStripMachine orEquipmentAnalogSourceAnalogSourceAnalogSourceFigure 37: Analog Input Shield Grounding with a Terminal Strip
PACSystems* RX3i System ManualSection 3GFK-2314TSept. 2019Installation56Appendix A:Analog Input Shield Groundingto Common ConnectionsIn some applications, noise rejection can be improved by connecting the source common points together atthe source end, then connecting a common line to the module at only one module COM terminal. That willeliminate multiple grounding or ground loops that could cause false input data. The common connectionshere are shown in red (bold) in Figure 38.AnalogSourceAnalogInputModuleCOMAnalogSourceAnalogSourceAnalogSourceFigure 38: Analog Input Shield Grounding to Common Connections
PACSystems* RX3i System ManualSection 3GFK-2314TSept. 2019Installation57Appendix B:Analog Input ShieldsConnected to Module TerminalBoardIt is usually preferable to ground cable shields at the source end. If that is difficult, or if electrical noise is not aconcern, it may be acceptable to ground cable shields at the analog input module end. They can beconnected to one of the GND terminals of the module (which are connected to frame ground through an

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Term
Spring
Professor
NoProfessor
Tags
Experience, power supply, Input output

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