VXI VT1538A user manual Stepper Motor Control Use the command, Stepping mode values

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Stepper Motor Control Use the command

SOURce:FUNCtion:STEPper <preset_pos>,<mode>,<max_vel>,<min_vel >,(@<ch_list>)

to control stepper motors. The E1538 can operate 2 or 4 phase motors in full, and half step mode. Position values are sent from the algorithm to the first channel of a 2 or 4 channel "motor group". The algorithm reads the current position from the second channel of the group.

Four-phase stepper motors that require less than 100mA phase current can be directly driven by the SCP. See Figure 29 for a connection diagram that also shows the required user-supplied output protection components.

•<preset_pos> defines the position count at algorithm start-up.

•<mode> is used to select the stepping mode. the allowable values are:

Table 1. Stepping <mode> values


	<mode> string	Stepping Mode	Speed	Channel

	MFSFC2	Full	Full	2

	MFSFC4	Full	Full	4

	MFSHC2	Full	Half	2

	MFSHC4	Full	Half	4

	MHSFC2	Half	Full	4

•<min_vel> is specified in steps per second and is the beginning step rate at the start of the 14 or 38 step ramp-up to <max_vel>.

<max_vel> is specified in steps per second and is the maximum step rate that will be sent to the motor after ramp-up is complete.

Figure 25 shows the relationship between these parameters. A related error message: 3120, "Minimum velocity parameter must not exceed maximum velocity parameter."

Figure 25. Relationship of min_vel, and max_vel

•<ch_list> specifies the channels that will control stepper motors. A

Agilent E1538A Enhanced Frequency/Totalize/PWM SCP 37

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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