HP E1367A, E1366A manual Relay Life, End of Life Detection Replacement Strategy

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Relay Life

End of Life

Detection

Replacement

Strategy

Electromechanical relays are subject to normal wear-out. Relay life depends on several factors. The effects of loading and switching frequency are briefly discussed below:

Relay Load. In general, higher power switching reduces relay life. In addition, capacitive/inductive loads and high inrush currents (e.g., turning on a lamp or starting a motor) reduces relay life. Exceeding specified maximum inputs can cause catastrophic failure.

Switching Frequency. Relay contacts heat up when switched. As the switching frequency increases, the contacts have less time to dissipate heat. The resulting increase in contact temperature also reduces relay life.

A preventative maintenance routine can prevent problems caused by unexpected relay failure. The end of the life of the relay can be determined by using the three methods described below. The best method (or combination of methods), as well as the failure criteria, depends on the application in which the relay is used.

Contact Resistance. As the relay begins to wear out, its contact resistance increases. When the resistance exceeds a predeterminded value, the relay should be replaced.

Stability of Contact Resistance. The stability of the contact resistance decreases with age. Using this method, the contact resistance is measured several (5-10) times, and the variance of the measurements is determined. An increase in the variance indicates deteriorating performance.

Number of Operations. Relays can be replaced after a predetermined number of contact closures. However, this method requires knowledge of the applied load and life specifications for the applied load.

The replacement strategy depends on the application. If some relays are used more often, or at a higher load, than the others, the relays can be individually replaced as needed. If all the relays see similar loads and switching frequencies, the entire circuit board should be replaced when the end of life approaches. The sensitivity of the application should be weighed against the cost of replacing relays with some useful life remaining.

Note Relays that wear out normally or fail due to misuse should not be considered defective and are not covered by the product’s warranty.

Appendix A

HP E1366A/E1367A RF Multiplexer Specifications 63

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Contents Contents HP E1366A/E1367A RF Multiplexers Command Reference HP E1366A/E1367A RF Multiplexer Specifications HP E1366A/67A RF Multiplexers User’s Manual Contents HP E1366A & E1367A RF Multiplexer Modules User’s Manual Documentation History According to ISO/IEC Guide 22 and EN December 5HP E1366A & E1367A RF Multiplexer Modules User’s Manual Reader Comment Sheet Measurement Systems DivisionHP E1366A & E1367A RF Multiplexer Module User’s Manual Using This Chapter Getting Started with the HP E1366A/E1367A RF MultiplexersMultiplexer Module Description Multiplexers Switching Diagram Address Typical ConfigurationSpecifying Scpi Commands Programming the Multiplexer ModuleMultiplexer Channel Numbers Multiplexer Card NumbersExample RF Multiplexer Channel Lists/Ranges Initial OperationPage Chapter Configuring the HP E1366A/E1367A RF Multiplexers Configuring the HP E1366A/E1367A RF MultiplexersConfiguring the HP E1366A/E1367A RF Multiplexers Chapter Connecting User InputsHewlett-Packard BNC Cables Standard Configuration Typical Multiplexer ConfigurationsTypical Tree Configuration Typical Matrix-Type Configuration Matrix-Type ConfigurationRF Multiplexer Component Locations Changing Multiplexer ComponentsConfiguring the HP E1366A/E1367A RF Multiplexers Chapter Chapter Using the HP E1366A/E1367A RF Multiplexer Module Using the HP E1366A/E1367A RF Multiplexer ModuleMultiplexer Commands Switching ChannelsUsing the HP E1366A/E1367A RF Multiplexer Module Chapter Example Standard SwitchingTree Switching Example Tree SwitchingQuery Channel States. Use CLOSe? channellist or Example Matrix-Type SwitchingScanning Channels Example Scanning Using Trig Out PortScanning Channels Comments Scanning with External Instruments Scanning Channels CommandsUsing Scanning Trigger Sources Understanding the HP E1366A/E1367A RF MultiplexersUnderstanding the HP E1366A/E1367A RF Multiplexers Chapter Scanning Trigger Sources Scanning with External Device Example Scanning with External DeviceExample Scanning Using Trig Out Event Ports Example Scan Complete Interrupt Using the Scan Complete BitScpi Command Format HP E1366A/E1367A RF Multiplexers Command ReferenceCommand Types Common Command FormatHP E1366A/E1367A RF Multiplexers Command Reference Chapter Semicolon between the commands. For example Example Stopping a Scan with ABORt Scpi Command ReferenceABORt Subsystem Syntax ABORtParameters Subsystem Syntax ARMExample Query Number of Scanning Cycles Example Enabling the Monitor Mode DISPlaySubsystem Syntax DISPlay Example Select Module #2 in a Switchbox for Monitoring Example Enabling Continuous Scans ∙ Non-Continuous Scanning Operation This is enabled with∙ Stopping Continuous Scans See the ABORt command INITiateExample Query Continuous Scanning State Subsystem Syntax OUTPut Example Enable Trig Out PortExample Query Trig Out Port Enable State OUTPutExample Closing Multiplexer Channels ROUTeSubsystem Syntax ROUTe Comments ∙ Closing Channels To closeComments ∙ Opening Channels To openExample Opening Channels Open Example Scanning Using External Devices Example Selecting Paired-Channel Scanning Example Query Scan Mode∙ Returned Data after sending the STATusOPERationEVENt? ∙ Setting Bit 7 of the Status RegisterSTATus Subsystem Syntax STATusSYSTem CTYPe?Subsystem Syntax SYSTem Example Reading the Model Number of a Card #1 Module ∙ RF Multiplexers Power-On State The power-on state is allExample Setting Card #1 Module to its Power-on State Comments ∙ RF Multiplexers Model NumberExample Advancing Scan Using the TRIGger Command TRIGgerSubsystem Syntax TRIGger ∙ Trig Out Port Shared by Switchboxes See the OUTPut command Example Scanning Using External Triggers Example Scanning Using Bus TriggersExample Query Trigger Source Command Title Description Ieee 488.2 Common CommandsCommands for the RF Multiplexer modules used in a switchbox Command Quick ReferenceGeneral HP E1366A/E1367A RF Multiplexer SpecificationsInput Characteristics AC Performance Appendix a HP E1366A/E1367A RF Multiplexer SpecificationsTypical Crosstalk channel-channel Cooling/Slot HP E1366A/E1367A RF Multiplexer Specifications Appendix aRelay Life End of Life Detection Replacement StrategyHP E1366A/E1367A RF Multiplexer Specifications Appendix a HP E1366A/E1367A Multiplexer Registers Appendix B HP E1366A/E1367A Multiplexer RegistersID Register ID/Device Type Registers Status/Control Register Channel Enable RegistersAddressing the Registers Reading the RegistersWriting to the Registers HP E1366A/E1367A Multiplexer Registers Appendix B Appendix C HP E1366A/E1367A RF Multiplexer Error Messages HP E1366A/E1367A RF Multiplexer Error MessagesHP E1366A/E1367A RF Multiplexer Error Messages Appendix C HP E1366A/67A RF Multiplexers User’s Manual Index IndexHP-IB HP E1366A/67A RF Multiplexers User’s Manual Index HP E1366A/67A RF Multiplexers User’s Manual Index