HP 6623A, 6624A, 6621A manual Overcurrent Protection OCP, Multiple Output Storage & Recall

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To enable an output after it went into overvoltage, you must first remove the overvoltage condition and then send the OV reset command.

To reset output 1 send:

OVRST 1

If you send the reset command without first removing the OV condition, the supply will fire the OV again.

NOTE	If the programmable OV fails, the supply has a fixed OV circuit which will fire the SCR crowbar if the
	voltage exceeds 120% of the maximum rated output. The fixed OV circuit will also fire the SCR
	crowbar if the supply is off (line cord disconnected) and an external source is supplying voltage which
	exceeds 120% of the maximum rated output.

Overcurrent Protection (OCP)

The OCP is a protection feature employed by the power supply to guard against excessive output currents. When the output enters the + CC mode and the OCP is enabled, the OCP circuit down programs the output voltage and disables the output.

To enable the OCP, for output channel 1, send the command

OCP 1,1

To disable the OCP, send the command

OCP 1,0

You can find out the OCP setting by sending the following query and addressing the power supply to talk.

OCP? 1

The response from the power supply is either a "0" to indicate that OCP is off or a ''1" to indicate that it is on. To reset the output channel after an overcurrent trip, you can either disable the OCP and send the reset command, or you can reduce the output current below the programmed current and then send the reset command. To reset output 1, send the command:

OCRST 1

NOTE	The supply can report a fault condition when an output is in overvoltage or overcurrent. Although the
	OVRST and OCRST commands reenable the output, they do not clear the fault register. As a
	housekeeping measure, it is advisable to always clear the fault register by querying its value after an OV
	or OC reset.

Multiple Output Storage & Recall

The power supply has 10 internal registers each of which can store the voltage and current settings of all the outputs. By storing voltage and current settings for all outputs and recalling them later, you can have significant savings in programming time. (See Supplemental Characteristics in Table 1-1).

72 Remote Operation

Image 72

Contents Operating Manual HP Part NoCertification Safety Summary Safety Summary Symbol DescriptionDeclaration of Conformity EMCInstallation Procedures Appendix A--Calibration ProcedureAppendix C--Command Summary Appendix D--Error MessagesTable Of Contents Remote Operation Local OperationCommand Summary Error MessagesCalibration Programming With The Series 200/300 ComputerPage Safety Considerations General InformationIntroduction Instrument and Manual IdentificationAccessories DescriptionOutput Combinations Available Model Basic Operation Output Low Range Values High Range ValuesHP-IB Board Output Boards Specifications Qualifying ConditionsDefinitions Output Response Characteristics Specifications Source EffectSupplemental Characteristics Outputs Low High Voltage Temperature CoefficientOutputs Low High Voltage Programming Resolution Readback ResolutionAC Input Power and Current Command Processing Time see FigureSafety Agency Compliance Dimensions all modelsOutput Impedance Low Voltage High Voltage 80 W Low VoltageGeneral Information General Information General Information General Information Installation Initial InspectionLocation and Cooling Input Power Requirements Line FuseLine Fuses 100/120 2110-0342 220/240 2110-0055Power Cord Line Voltage ConversionHP-IB Interface Connector Page Front Panel Controls and Indicators Getting StartedTurning On Your Supply LCL key HP-IB Status AnnunciatorsPower Supply Status AnnunciatorsAlphanumeric LCD System Control KeysOutput Control Keys Line Switch Numeric Entry KeysNormal Self Test Indications Checking Out Your Supply Using Local Control Sample Self-Test Failure DisplayVoltage Test Overvoltage TestCurrent Test Introduction To Remote Operation Iset EnterOCP Enter/Output StatementsSending a Remote Command OutputReading the HP-IB Address AddrOften Used Commands Getting Data From The SupplyDisp a Disp a Returning the Supply to Local Mode Output Connections and Operating Information Output RangesProtection Features Operating QuadrantsRange Selection Typical Output Range Characteristics Connecting the Load Page Wire Bundled 10 a 20 a FeetCross Section Meters Area in mm2 Remote Voltage Sensing Multiple LoadsPositive and Negative Voltages Remote Voltage Sensing Remote Sense ConnectionsOutput Type Formula Output Noise ConsiderationsProgramming Response Time with an Output Capacitor Open Sense LeadsOvervoltage Trigger Connections External Trigger CircuitEquivalent Internal OV Trigger Circuit Power Supply Protection Considerations Battery ChargingParallel Operation Maximum Allowable Voltage Setting CV OperationCC Operation Remote SensingSeries Operation 13. Series Connections with Local Sensing CV OperationSpecifications for Series Operation 14. Series Connections with Remote SensingPage Page Remote Operation HP-IB OperationInterface Function HP-IB Address Selection Power-On Service Request PON Programming SyntaxNumeric Data Sheet 1 of 2. Syntax Forms for Power Supply Commands Sheet 2 of 2. Syntax Forms for Power Supply Commands Fault ? VsetIset OvsetPage Power Supply Commands Initial Conditions Voltage Programming Current ProgrammingRange Switching Output On/Off Overvoltage OV ProtectionOVSET? Overcurrent Protection OCP Multiple Output Storage & RecallClear Command Status ReportingUNR +CC ASTS?FAULT? UNMASK?Unmask 2,XXX Bit Assignment of the Serial Poll RegisterService Request Generation SRQ? PON ?Reprogramming Delay RQS BitDisplay On/Off Other Queries Front Panel ExplanationResponse Code TEST? Responses Code ExplanationPage Local Mode Local OperationLocal Control Of Output Functions GeneralSetting Voltage Setting CurrentSetting Overvoltage Protection Resetting Overvoltage ProtectionResetting Overcurrent Protection Displaying the Contents of the Fault RegisterSetting the Reprogramming Delay Setting the Supplys HP-IB AddressLocal Control Of System Functions ConditionDisplaying Error Messages Addr EnterSTO Enter RCL EnterPage Calibration Procedures Test Equipment and Setup RequiredFigure A-1. Calibration Setup General Calibration Procedure Are not stored. Exercise care when moving the leads Calibration Program 10 ! Calibration ExampleClear Voltmeter Output Buffer PauseInput ANY More Outputs to CALIBRATE? Y or N,X$ Disp END of Calibration ProgramFnend Page Page Programming With a Series 200/300 Computer Path NamesVoltage and Current Programming Voltage and Current Programming With Variables Voltage and Current ReadbackProgramming Power Supply Registers Print OUTPUT1 is in CV Mode END ifService Request and Serial Poll Present StatusEnable Intr OFF IntrPrint Overvoltage on Output #1 Print Overvoltage on Output #2Error Detection Programming Outputs Connected In Parallel Stored Operating StatesInput Enter Voltage LIMIT,V Input Enter Operating VOLTAGE,V1Programming Outputs Connected In Series Input Enter the Desired Current Limit POINT,ICommand Summary Table C-1. Command SummaryCommand Description Table C-l. Command Summary PON? ROM?Previously Error Codes and Messages Power-On Self Test Messages Error ResponsesTable D-l. Power-On Self Test Error Message Test ResponsesTable D-2. Error Responses Error Code Message Explanation ERR? query ERR keyTable D-3. TEST? Responses Response Code Explanation TEST? queryPage Manual Backdating Make ChangesGenerally Applicable Annotations II. CE92 Product Specific Annotations6621A 6623AOr contact EuropeFar East Latin America