VXI VT1538A user manual Init

Page 53

exceeds the time-out period (i.e. frequency below LIMit:LOWer), then a frequency of 0 Hz will be returned to the E1415/19/22 algorithm.

Typical use for this command is to allow the user to bound the period of time that is allowed for making a frequency measurement, thus, preventing the SCP from “hanging” during measurement.

In this case, typically, the LIMit:LOWer frequency would be the same as, or slower than the frequency associated w/the APERture time.

An unusual (but valid) use is to set the LIMit:LOWer frequency to be greater than the frequency associated with the APERture period, which can provide a means to abort a frequency measurement if at any point during the measurement, the input waveform frequency is slower than the configured LIMit:LOWer frequency.

Note The lower limit set by SENS:FREQ:LIM:LOW is for a single signal period, not the sum of NPERiods. Unless at least one period of the input signal exceeds the limit value set, then NPERiods will be measured and averaged to return a reading. For instance if;

SENS:FREQ:MODE NPERiods,<ch_list> SENS:FREQ:NPERiods 255 SENS:FREQ:LIMit:LOWer 0.01667 ! 60 second period

...

INIT

As long as the input signal frequency is slightly greater than the LIMit:LOWer frequency, then the SCP will not time-out and will take 255 * (~60sec) = ~255 minutes to take a single frequency measurement.

Alternatively, if even one of the input waveforms has a frequency that is lower than the LIMit:LOWer frequency, then 0 Hz would be immediately returned to the E1415/19/22 algorithm.

Related Commands: SENS:FREQ:APER, SENS:FREQ:LOW?

*RST Condition: is “MINimum” frequency (i.e. 0.01667 Hz [period = 60sec]).

Send with VXIplug&play Function: hpe14XX_cmd(...)

Agilent E1538A Enhanced Frequency/Totalize/PWM SCP 49

Image 53
Contents VT1538A VXI Technology, Inc Introduction Support Resources User’s and Scpi Programming Manual Page About this Manual Agilent E1538A Enhanced Frequency/Totalize/PWM SCPIntroduction Identifying the Plug-on Important Switch Location and Example Settings Setting Configuration SwitchesConnecting To The Terminal Module InstallationE1419A Option 11 Terminal Module Connections Recommended Signal ConnectionsRecommended Connections and Voltage Limits Input and Output CharacteristicsE1538A Input/Output Characteristics VRS Mode Input Operation SCP Channels 0 & 1 onlyShows the VRS mode input characteristics Programming With Scpi CommandsSetting the Input Threshold Level Configuring I/O DirectionInppol Norm Determining the Input Threshold LevelTo set channels 40 through 43 to input digital states Reading Static Digital StateInit SENSDATACVT? @44 Totalize Positive or Negative Edge State ChangesAbout Period Frequency Measurements SENSDATACVT? @45 SENSDATACVT? @45 Agilent E1538A Enhanced Frequency/Totalize/PWM SCP Agilent E1538A Enhanced Frequency/Totalize/PWM SCP Sensfuncquad 0,@148,149 Sense Quadrature PositionRPS Sense Rotational Velocity Example of Rotational Velocity SenseOutput Static Digital State Controlling Output PolarityVariable Width Pulse Per Trigger Variable Width Pulse Train PWM Variable Frequency Fixed Width Pulse Train FM Variable Frequency Square-Wave Pulse Train Rotationally Positioned Pulse Output Rotational Pulse Command Usage Algupdate Init RST Sensfuncrvel 12,MISS,@140 Example of variable position, preset widthVariable Position, Width Preset by Time Example of variable width by angle, preset position Fixed Position, Variable Width by Angle Example of variable width by time, preset positionALGSCALAR’ALG1’,’Width2’,.010 Stepping mode values Stepper Motor Control Use the commandSensfuncvolt @100 Full Step Mode, Full and Half Speed, 4-Channel Page RST and *TST important Command Syntax For newer Units only Scpi Command ReferenceCommand Syntax For newer Units only Discussed INPutPOLarity? INPutPOLarityParameters CommentsINPutTHResholdLEVel? Level can be set to a resolutionINPutTHResholdLEVel Send with VXIplug&play Function hpe14XXcmdReal64Q OUTPutPOLarityOUTPutPOLarity? SENSeFREQuencyAPERture SENSeFREQuencyLIMitLOWer Related Commands SensfreqaperSENSeFREQuencyAPERture? Init SENSeFUNCtionCONDition Related Commands INPutPOLaritySENSeFREQuencyLIMitLOWer? SENSeFUNCtionPERiod SENSeFUNCtionFREQuencySENSeFUNCtionQUADrature SENSeFUNCtionPWIDthSENSeFUNCtionRVELocity RPS SENSeFUNCtionTOTalize SENSePERiodAPERture SENSePERiodLIMitUPPer SENSePERiodAPERture?Init SENSePERiodMODE SENSePERiodLIMitUPPer?SENSePERiodNPERiods Related Commands SENSePERiodMODESENSePERiodMODE? Send with VXIplug&play Function hpe14XXcmdInt32Q SENSePERiodNPERiods?SENSePERiodRANGeUPPer RST Condition is Send with VXIplug&play Function hpe14XXcmd SENSeTOTalizeRESetMODESENSePERiodRANGeUPPer? SOURceFMSTATe SENSeTOTalizeRESetMODE?Send with VXIplug&play Function hpe14XXcmdInt16Q SOURceFMSTATe?SOURceFUNCtionRPULse SOURceFUNCtionSHAPePULSe SOURceFUNCtionSHAPeCONDitionComments Send with VXIplug&play Function hpe14XXcmd SOURceFUNCtionSHAPeSQUareSOURceFUNCtionSTEPper Relationship of minvel, and maxvel Usage See Stepper Motor Control on SOURcePULMSTATeSOURcePULSePERiod SOURcePULMSTATe?SOURcePULSeWIDTh SOURcePULSePERiod?33,554,430 to 33,554,430 SOURcePULSeWIDTh?SOURceRPULsePOSitionANGLe Usage SOURceRPULsePOSitionANGLe?SOURRPULseVARType SOURceRPULseWIDThANGLe SOURRPULseVARType?00000787 to SOURceRPULseWIDThANGLe?SOURceRPULseWIDThTIME SOURceRPULseWIDThTIME? General Specifications SpecificationsFrequency Measurement Pulse Width Measure Rotational Pulse Source