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VXI VT1538A User's Manual

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1. Parameters Parameter Parameter Range of Default Name Type Values Units enable boolean uint16 1101 ON OFF none ch_list string 100 163 none Comments This command is coupled with the SOURce FM command If the FM state is enabled then the PULM state is disabled If the PULM state is enabled then the FM state is disabled If both the FM and the PULM states are disabled then the PULSe channel is in the single pulse mode e If the channels specified are not on a Frequency Totalize SCP an error will be generated e RST Condition SOUR PULM STATE OFF Send with VXIplug amp play Function hpel14XX_cmd Agilent E1538A Enhanced Frequency Totalize PWM SCP 69 SOURce PULM STATe SOURce PULM STATe lt channeb returns the pulse width modulated mode state for the PULSe channel in lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments Channel must specify a single channel Returned Value returns 1 on or 0 off The type is int16 Send with VXIplug amp play Function hpel4XX_cmdInt32_Q SOURce PULSe PERiod SOURce PULSe PERiod lt period gt lt ch_list gt sets the fixed pulse period value on a pulse width modulated pulse channel This sets the frequency 1 period of the pulse width modulated pulse train Parameters Parameter Parameter Range of
2. Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must be a single channel on an E1538A SCP Returned Value 01667 to 250 The type is float32 Send with VXIplug amp play Function hpel14XX_cmdReal64_Q SENSe FUNCtion CONDition SENSe FUNCtion CONDition lt ch_list gt sets the SENSe function to input the digital state for channels in lt ch_list gt See Reading Static Digital State on page 14 Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Comments The E1538 SCP senses the single bit digital state on each channel specified by this command e If the channels specified are not on a digital SCP an error will be generated Use the INPut POLarity command to set input logical sense Related Commands INPut POLarity RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpel4XX_cmd Usage See Reading Static Digital State on page 14 To set upper 4 bits of E1538 at SCP position 5 to digital inputs send 50 Agilent E1538A Enhanced Frequency Totalize PWM SCP SENS FUNC COND 144 147 SENSe FUNCtion FREQuency SENSe FUNCtion FREQuency lt ch_list gt sets the SENSe function to frequency for channels in lt ch_list gt Also configures t
3. Related error message 3127 Undefined E1538 Stepper motor mode The range of position values that an algorithm can send for the full speed SEF mode is 0 to 65 535 The range of position values that an algorithm can send for the half speed SH mode is 0 to 32 767 e lt min_vel gt is specified in steps per second and is the beginning step rate at the start of the 14 or 38 step ramp up to lt max_vel gt The lt min_vel gt should be a step rate that the motor can achieve from a standstill without missing a step lt min_vel gt can range from 128 to 40 000 64 to 40 000 for half speed SH modes e lt max_vel gt is specified in steps per second and is the maximum step rate that will be sent to the motor after ramp up is complete lt max_vel gt can range from 128 to 40 000 64 to 40 000 for half speed SH modes The increase in step rate from lt min_vel gt to lt max_vel gt will occur in 14 steps for a 2 Channel configuration and will occur in 38 steps for a 4 channel configuration Figure 25 shows the relationship between these parameters A related error message 3120 Minimum velocity parameter must not exceed maximum velocity parameter Velocity Profile lt max_vel gt steps second lt min_vel gt steps second gt standstill gt 14 step ramp up down oe for 2 Channels gt lt 38 step ramp up down for 4 Channels Figure 31 Relationship of min
4. INITiate here Algorithm Executions i G l l l i Algorithm data to 9 939 0 060 0 045 0 090 output channel gt lt 30mS 33 gt d 60mS 66 gt 45mS 50 90mS m 100 a Signal at Output Channel k I Preset Period gt 90mS gt 90mS gt 90mS gt 90mS e Figure 17 Output Pulse Width Modulated Signal 26 Agilent E1538A Enhanced Frequency Totalize PWM SCP Variable Frequency Fixed This means that the E1538 outputs a continuous train of pulses whose Width Pulse Train FM frequency is controlled by the algorithm The logic 1 level pulse width is set by a SCPI command before INIT Use the following command sequence SOURce FUNCtion PULSe lt ch_list gt to enable pulse generation SOURce FM STATe ON lt ch_list gt to select the FM mode SOURce PULSe WIDTh lt width gt lt ch_list gt to pre set the pulse width of the logic 1 portion of the waveform lt width gt can range from 7 87USec to 7 812mSec The frequency value sent by the algorithm can range from 128Hz to 40KHz 2 Sout The frequency resolution is TOENI To configure channel 45 to output variable frequency continuous train with fixed pulse width SOUR FUNC PULS 145 channel sources pulses SOUR FM ON 145 and continuous pulse train SOUR PULS WIDT 001 1 45 I msec fixed pulse width Th
5. 1sec Range 4 0 sec provides period measurement in the range 40usec 4sec e MINimum 1 0 MAXimum 4 0 Note 1538As have a possible settings conflict Agilent E1538A Enhanced Frequency Totalize PWM SCP 61 If SENSe PERiod RANGe 1 0 then settings conflict if 1 0sec lt APERture lt 4 0sec If SENSe PERiod RANGe 4 0 then settings conflict if 0 01sec lt APERture lt 0 04sec The E1415 19 22 driver will report these Settings Conflicts at INITiate time with the following error message 3129 Incompatible Aperture and Range values SCP x Related Commands SENSe PERiod NPERiods RST Condition is 1 Send with VXIplug amp play Function hpel4XX_cmd SENSe PERiod RANGe UPPer SENSe PERiod RANGe UPPer lt channel gt returns the current setting of upper period limit Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must be single channel on an E1538A SCP e RETURNS float32 configured upper period time range for given ch Response is in seconds Returned value either 1 or 4 Send with VXIplug amp play Function hpel14XX_cmdReal64_Q SENSe TOTalize RESet MODE SENSe TOTalize RESet MODE lt select gt lt ch_list gt sets the mode for resetting totalizer channels in lt ch_list gt Parameters Parameter Parameter Range of Default Na
6. 3113 Channel specified is not in same SCP as reference channel 3114 First channel in SCP can not be used in RPULse output channel list 3118 Incomplete setup information for RPULse function Notes 1 There must be one and only one channel on the same SCP that is set to SENSe FUNCtion RVELocity This sense channel provides the rotational velocity and index reference that the SCP uses to position the output pulses at a desired rotational angle This is the lt ref_channel gt seen above The lower velocity limit for RPULse is 108 teeth per Second TPS for extra tooth wheels and 384TPS for missing tooth wheels For example a 60 tooth wheel would need to rotate at a minimum of 108RPM if it had an extra tooth but at 384RPM minimum with a missing tooth Long duration pulses that begin and end within a wheel s missing tooth area can exhibit significant jitter Use an extra tooth wheel for Agilent E1538A Enhanced Frequency Totalize PWM SCP 65 these applications See Figure 30 OK S a Not Reccommended Figure 30 For Long Pulses Use Extra Tooth Wheel Send with VXIplug amp play Function hpe14XX_cmd Usage SENSE FUNC RPULSE 1 08 1 14 11 5 reference chan is 108 pulse output on channels 114 and 115 SOURce FUNCtion SHAPe CONDition SOURce FUNCtion SHAPe CONDition lt ch_list gt sets the SOURce function to output digital patterns to bits in lt ch_list gt
7. Technology VTIS38A ENHANCED FREQUENCY TOTALIZE PWM SIGNAL CONDITIONING PLUG ON USER S MANUAL 82 0093 000 Release April 28 2003 VXI Technology Inc 2031 Main Street Irvine CA 92614 6509 949 955 1894 VXI Technology Inc www vxitech com INTRODUCTION On May 1 2003 VXI Technology Inc acquired Agilent Technology s mechanical data acquisition product segment During the transition period Agilent branded manuals will be provided with the dynamic and static data acquisition products until the manuals have been rebranded The following products are provided for in this manner Dik DA Prod VTI Part Number Agilent Part Number Description VT1432A E1432A 16 Channel 51 2 kSamples s Digitizer Plus DPS VT1433B E1433B 8 Channel 196 kSamples s Digitizer Plus DPS VT1434A E1434A 4 Channel 65 kSamples s Arbitrary Source VT3240A E3240A Voltage Input Breakout Box VT3241A E3241A ICP Voltage Input Breakout Box VT3242A E3242A 4 Channel Charge Voltage ICP Breakout Box VT3243A E3243A 4 Channel Microphone Voltage ICP Breakout Box VT2216A N2216A VXI SCSI Interface Module Static DAC Products VTI Part Number Agilent Part Number Description VT1413C E1413C 64 Channels Muxed to 16 Bit 100 kSamples s A D VT1415A E1415A Algorithmic Closed Loop Controller VT1419A E1419A Multi Function Measurement and
8. 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 PER MODE NPERiods lt ch_list gt SENS PER NPERiods 255 SENS PER LIMit UPPer 60 INIT When the input waveform period is slightly less than the upper period limit then the SCP will not time out and will take 255 60sec 255 minutes to take a single period measurement Alternatively if even one of the input waveforms has a period that exceeds the LIMit UPPer period then 0 sec would be immediately returned to the E1415 19 22 algorithm RST Condition is MAXimum i e 60 0sec Send with VXIplug amp play Function hpel4XX_cmd 58 Agilent E1538A Enhanced Frequency Totalize PWM SCP SENSe PERiod LIMit UPPer SENSe PERiod LIMit UPPer lt channel gt returns the upper period limit currently set for lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must be a single channel on an E1538A SCP RETURNS 004 to 60 Type is float32 SENSe PERiod MODE SENSe PERiod MODE lt mode gt lt ch_list gt selects the measurement interval mode the SCP will use to measure the signal period This can be set as a fixed amount of time APERture or a fixed number of sig
9. 554 430 1 degree up to 10 0000 RPS 0 to 360 degrees tooth to toothangle or 360 x 238 4nSec the larger of 128 RotPeriod 0 to Rotational Period see note 3 on page 65 238 4 nS 108 teeth per second 80 Agilent E1538A Enhanced Frequency Totalize PWM SCP 384 teeth per second
10. Agilent E1415 or E1419 User s Manual Connecting To The Terminal Module The SCP connections for the Terminal Modules are shown on the self adhesive labels that come with the SCP Use these to label terminal definitions on your terminal module The connections are shown in Figure 3 CX G dOS Y dos NN ES e IN TL aN Sn JS o o p of ro LO O TLa0 ao JO oO oO wf ro EO qn e038 Iols o o I Iv jo LZS 5398 o o of Em IO w6 eC 35 Ials oO oO af n IN SL aa sald E o o ef Ire Te SLZ zzjs oO oO gt z C of Zo Io Lis Ze18 oO o EJ EA pi Co eo i aay OC m mm mm a i ea m oo E Sa sy oO oe O NH 0 oO oO o nfn IN of ak Pe ts eo SLIn zn je actin zoja o o O orao Jogy ardo ToJo SL ro roje NL Io Ioj z _O oo wf a0 Dojo f uw Sogo OLro ele AL Io IroJN g O o 0 fo 322 zyje of a aT Jo oOoLIY b ah e aa NL IY IJN 0 o o o of a0 22 of a0 AON J OLIM moje Lee IJN o o _O o af aN aN Jo of aN AN Jo OLIN INJ SLIN INJN o o _O o aas es poe ao SLI IJS SLEE IFS Va o o oO o of se 22 g of 10 doje oLIo rojo aed p IoJN A 0 dos TdOS Zaos eas Z Figure 3 E1538A Terminal Module Connections Figure 4 shows the screw terminal Option 11 for the E1419A 7 Agilent E1538A Enhanced Freq
11. Default Name Type Values Units period numeric float32 25E 6 to 7 8125E 3 seconds resolution 0 238usec ch_list string 100 163 none Comments e If the channels specified are not on a Frequency Totalize SCP an error will be generated e RST Condition SOUR FM STATE OFF and SOUR PULM STATE OFF Related Commands SOUR PULM STATE SOUR PULS POLarity The variable pulse width control for this channel is provided by the algorithm language When the algorithm executes an assignment statement to this channel the value assigned will be the pulse width setting For example 0140 0025 set channel 43 pulse width to 2 5 msec Send with VXIplug amp play Function hpel4XX_cmd 70 Agilent E1538A Enhanced Frequency Totalize PWM SCP Usage SOUR PULS PER 005 140 set PWM pulse train to 200 Hz on channel 40 SOURce PULSe PERiod SOURce PULSe PERiod lt channel gt returns the fixed pulse period value on the pulse width modulated pulse channel in lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments e If the channels specified are not on a Frequency Totalize SCP an error will be generated Returned Value numeric period The type is float32 Send with VXIplug amp play Function hpel14XX_cmdReal64_Q SOURce PULSe WIDTh SOURce PULSe WIDTh lt pulse_width gt lt c
12. Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Comments The E1533 SCP sources 8 digital bits on the channel specified by this command The E1534 SCP can source 1 digital bit on each of the the channels specified by this command Send with VXIplug amp play Function hpel4XX_cmd SOURce FUNCtion SHAPe PULSe SOURce FUNCtion SHAPe PULSe lt ch_list gt sets the SOURce function to PULSe for the channels in lt ch_list gt Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Comments This PULSe channel function is further defined by the SOURce FM STATe and SOURce PULM STATe commands If the FM state is enabled then the frequency modulated mode is active If the 66 Agilent E1538A Enhanced Frequency Totalize PWM SCP PULM state is enabled then the pulse width modulated mode is active If both the FM and the PULM states are disabled then the PULSe channel is in the single pulse mode Send with VXIplug amp play Function hpe14XX_cmd SOURce FUNCtion SHAPe SQUare SOURce FUNCtion SHAPe SQUare lt ch_list gt sets the SOURce function to output a square wave 50 duty cycle on the channels in lt ch_list gt Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Commen
13. THR LEV 133 query 2nd chan on SCP pos 4 enter statement here returns threshold value Set Input Logic Sense Use INPut POLarity NORMal INVerted lt ch_list gt to configure input channel logic sense The operation is as follows INP POL NORM input voltage greater than the threshold level sends a value of 1 one to the algorithm channel specifier INP POL INV input voltage greater than the threshold level sends a value of 0 zero to the algorithm channel specifier To configure channels 40 to 43 to sense low input as logic 1 INP POL INV 140 143 Agilent E1538A Enhanced Frequency Totalize PWM SCP 13 Reading Static This means reading a channel s current digital state when an algorithm Digital State executes This is the default function assigned to all digital input channels after RST and at power up To set individual channels to this function use the SCPI command SENSe FUNCtion CONDition lt ch_list gt The value returned to an algorithm is a floating point representation of 0 or 1 depending on the state of the input signal and the channel s INP POL setting To set channels 40 through 43 to input digital states RST SENS FUNC COND 140 143 default for all dig inputs ALG DEF ALG1 writecvt 1140 40 writecvt I141 41 writecvt 142 42 writecvt 143 43 INIT do loop SENSE DATA CVT 40 43 read 4 CVT values end loop Signal sampled only at the beginning of each algorithm execution N
14. 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 e lt preset_pos gt defines the position count at algorithm start up e lt mode gt is used to select the stepping mode the allowable values are Table 1 Stepping lt mode gt values lt mode gt 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 e lt min_vel gt is specified in steps per second and is the beginning step rate at the start of the 14 or 38 step ramp up to lt max_vel gt lt max_vel gt 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 Velocity Profile SS standstill T doen EREET l 14 step ramp up down 5 a i for 2 Channels gt lt 38 step ramp up down for 4 Channels F
15. and converts it into units of revolutions per second RPS This function can only be linked to the E1538 s first channel The function works for wheels that have either a missing or an extra tooth to mark their index position Figure 14 shows a wheel sensed with a variable reluctance sensor using the VRS input option but any wheel sensing method is applicable as long as it provides a digital output to the RVEL channel o 100 000 RPS nteeth The value read by the algorithm can range fro As well as sensing rotational velocity SENS FUNC RVEL provides the reference position to the SOUR FUNC RPULse function that generates angular positioned pulses See page 30 for more information on RPULse To assign a channel to sense rotational velocity use the command SENSe FUNCtion RVELocity lt n_teeth gt lt index_type gt lt ch_list gt lt n_teeth gt is the number of teeth that the wheel would have if it didn t have missing or extra teeth For example we would set lt n_teeth gt to 12 for the wheel shown in Figure 14 even though with the missing tooth there are only 11 lt n_teeth gt can range from 3 to 255 22 Agilent E1538A Enhanced Frequency Totalize PWM SCP lt index_type gt can be either of the strings MISSing or EXTRa lt ch_list gt must be the first channel on the SCP but can contain more than one channel provided that each channel is on a separate E1538 See following note The related Error
16. output channels in lt ch_list gt Parameters Parameter Parameter Range of Default Name Type Values Units select discrete string NORMal INVerted none ch_list string 100 163 none Comments e If the channels specified do not support this function an error will be generated Related Commands INPut POLarity OUTPut POLarity e RST Condition OUTP POL NORM for all digital channels Send with VXIplug amp play Function hpel14XX_cmd Usage OUTP POL INV 144 invert output logic sense on channel 44 OUTPut POLarity OUTPut POLarity lt channel gt returns the polarity on the digital output channel in lt channel gt 46 Agilent E1538A Enhanced Frequency Totalize PWM SCP Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments Channel must specify a single channel Returned Value returns one of NORM or INV The type is string Send with VXIplug amp play Function hpe14XX_cmdString_Q SENSe FREQuency APERture SENSe FREQuency APERture lt aperture gt lt ch_list gt sets the time allowed to determine signal frequency and return a reading to the algorithm When APERture is large enough to contain more than one signal period the SCP measures and averages the number of signal periods that will fit within this APERture time If the specified APERture is less than the input signal period the SCP stretches the aper
17. resources for this product are available on the Internet and at VXI Technology customer support centers VXI Technology World Headquarters VXI Technology Inc 2031 Main Street Irvine CA 92614 6509 Phone 949 955 1894 Fax 949 955 3041 VXI Technology Cleveland Division VXI Technology Inc 7525 Granger Road Unit 7 Valley View OH 44125 Phone 216 447 8950 Fax 216 447 8951 VXI Technology Lake Stevens Instrument Division VXI Technology Inc 1924 203 Bickford Snohomish WA 98290 Phone 425 212 2285 Fax 425 212 2289 Technical Support Phone 949 955 1894 Fax 949 955 3041 E mail support vxitech com See http www vxitech com for worldwide support sites ay Agilent 75000 Series C E i Agilent Technologies E1538A Enhanced Frequency Totalize PWM Signal Conditioning Plug on User s and SCPI Programming Manual Where to Find it Online and Printed Information System installation hardware software VXIbus Configuration Guide Agilent VIC VXI installation software Module configuration and wiring This Manual SCPI programming This Manual VXI plug amp play programming VXIplug amp play Online Help VXI plug amp play example programs VXIplug amp play Online Help VXIplug amp play function reference VXI plug amp play Online Help Soft Front Panel information VXI plug amp play Online Help VISA language information Agilent VISA User s Guide Agilent VEE p
18. 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 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 lt ch_list gt 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 amp play Function hpe14XX_cmd Agilent E1538A Enhanced Frequency Totalize PWM SCP 49 SENSe FREQuency LIMit LOWer SENSe FREQuency LIMit LOWer lt channel gt returns the lower frequency limit currently set for lt channel gt
19. steps a Figure 26 Full Step Mode Full and Half Speed 2 Channel 38 Agilent E1538A Enhanced Frequency Totalize PWM SCP SCP Channel n 0 4 Algorithm sends position value to this channel SCP Channel n 1 Algorithm reads position value from this channel SCP Channel n 2 SCP Channel n 3 4 steps SCP Channel n 0 4 Algorithm sends position value to this channel SCP Channel n 1 Algorithm reads position value from this channel SCP Channel n 2 4 Phase Unipolar be Om Stepper Motor Cer a ee ee D3 cee B2VN 4 bh be Figure 27 Full Step Mode Full and Half Speed 4 Channel 4 Phase Unipolar britain D1 Stepper Motor ame E Ey HEEN 3 JLH A L LA L g2 V p 7 Figure 28 Half Step Mode Full Speed 4 Channel Agilent E1538A Enhanced Frequency Totalize PWM SCP 39 4 Phase Unipolar 4 Stepper Motor Hnn directly connects SCP output transistors to stepper motor use OUTP POL INV current limit resistors ee Vsupply Rwinding Riimit lt 0 1A fly back protection diodes 4 places supply return V connected to channel Low terminals Figure 29 Directly Driving 4 Phase Stepper Motors 40 Agilent E1538A Enhanced Frequency Totalize PWM SCP RST and TST important The RST and power on condition true also after TST for output configured channels will output a logical one open drain output off You should keep this behavior in mind when applying the E1415 to yo
20. 0 to 16 777 215 none ch_list string 100 163 none Comments lt count_preset gt if included allows presetting the absolute counter associated with the channel pair All quadrature pairs in lt ch_list gt will be preset to the same value If not included the default count at algorithm start will be zero e lt ch_list gt must always specify both channels of a pair More than one pair can be specified Both channels of any pair must be adjacent lt ch_list gt can specify channels on more than one E1538 The channel numbers in lt ch_list gt must be in ascending order The related error messages are 3115 Channels specified are not in ascending order 3116 Multiple channels specified are not grouped correctly 3117 Grouped channels are not adjacent 3122 This multiple channel function must not span multiple SCPs The algorithm reads the current count through the low numbered channel The count is an unsigned 24 bit value ranging from 0 to 16 777 215 The counter can roll over from 16 777 2215 to 0 and roll under from 0 to 16 777 215 is 16 777 215 RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpe14XX_cmd Usage See Sense Quadrature Position on page 21 SENS FUNC QUAD 8192 142 143 pair 42 amp 43 will return quad count on ch 142 count preset SENSe FUNCtion RVELocity to 8192 SENSe FUNCtion RVELocity lt n_tee
21. Control VT1422A E1422A Remote Channel Multi Function DAC Module VT1501A E1501A Direct Input 8 Channel SCP VT1502A E1502A Low Pass Filter Signal Conditioning Plug On VT1503A E1503A Gain Filter SCP VT1505A E1505A Current Source SCP VT1506A E1506A 120 Q Strain Gauge SCP VT1507A E1507A 350 Q Strain Gauge SCP VT1508A E1508A 8 Channel Fixed x 16 Gain Filer SCP VT1509A E1509A 8 Channel Fixed x 64 Gain Filter SCP VT1510A E1510A 4 Channel Sample and Hold SCP VT1511A EI511A 4 Channel Transient Strain SCP VT1512A E1512A Low Pass Filter Signal Conditioning Plug On VT1513A E1513A Attenuator Input SCP VT1518A E1518A Resistance Measurement SCP VT1529B E1529B 32 Ch Remote Strain Conditioning and Voltage Unit VT1531A E1531A 8 Channel Voltage Output Signal Conditioning Plug VT1532A E1532A 8 Channel Current Output Signal Conditioning Plug On VT1533A E1533A 16 Bit Digital Input Output Signal Conditioning VT1536A E1536A Isolated 8 Bit Digital I O Signal Conditioning VT1538A E1538A Enhanced Frequency Totalize PWM Signal Conditioning VT1539A E1539A Remote Channel Signal Conditioning Plug On VT1563A E1563A 800 kSamples s 2 Channel Digitizer 14 Bits VT1564A E1564A 800 kSamples s 4 Channel Digitizer 14 Bits VT1586A E1586A Rack Mount Terminal Panel for 32 Channels When rebranded manuals become available they can be downloaded at http www vxitech com download asp VXI Technology Inc SUPPORT RESOURCES Support
22. ENS PER LIM UPP Aperture Time The aperture time is the time allowed to average multiple period and frequency measurements Function Aperture Range Frequency 1mSec to 1 Sec Period 2 ranges 1mSec to 1 Sec SENS PER RANGE 1 4mSec to 4 Sec SENS PER RANGE 4 78 Agilent E1538A Enhanced Frequency Totalize PWM SCP Auto Gating adaptive aperture 1mSec to 1Sec for Frequency 1mSec to 1Sec for Perid using SENS PER RANGE 1 4mSec to 4Sec for Perid using SENS PER RANGE 4 Rotational Velocity Measure Characteristics Extra Tooth Wheel or Missing Tooth Wheel Range in RPS to ae teeth teeth Accuracy 01 Resolution in RPS Creen P vi T104MH where f is n se per second Minimum Pulse Width 500 nS Pulse Width Measure Periods Averaged 1 to 255 Range 5uSto1s Accuracy 250nS 0 1 Resolution 59 6 nSec Frequency Source Range 64 Hz to 40 KHz Square Wave 128 Hz to 40 KHz other shapes Accuracy 0 01 Resolution ae 4 194MHz Pulse Source Range 7 87 usec to 1 f 7 87 msec continuous pulse 7 87 usec to 7 812 msec single pulse per trigger Accuracy 0 01 Resolution 238 4 nsec Agilent E1538A Enhanced Frequency Totalize PWM SCP 79 Rotational Pulse Source Characteristics Extra Tooth Wheel Missing Tooth Wheel Position angle range Position resolution Position width range angle Pulse width resolution angle Pulse width range time Pulse width resolution time Minimum Rot velocity 33 554 430 to 33
23. LG UPDATE INIT ALG SCALAR ALG1 Pos1 NewPos1 ALG SCALAR ALG1 Pos2 NewPos2 ALG SCALAR ALG1 Pos3 NewPos3 ALG UPDATE preset ch 45 s pulse pos to 60 preset ch 46 s pulse pos to 180 preset ch 47 s pulse pos to 300 start algorithm execution calculate values for NewPos n later adjust channel 45 s position while algorithm running later adjust channel 46 s position while algorithm running later adjust channel 47 s position while algorithm running values in update queue sent to variables Agilent E1538A Enhanced Frequency Totalize PWM SCP 31 a Index Position pulse width fixed by angle _ before INITiate command pulse width fixed by angle before INITiate command 0 6 8 0 D O A O OANE 50 amp b Bo g KA extra tooth wheel read by A T SENS FUNC RVEL channel 6 pulse position controlled in algorithm by angle RAN pulse width fixed by angle before INITiate command Figure 21 Variable Position Width Preset by Angle Rotational Pulse Mode Variable Angular Position Preset Pulse Width by time In this mode the angular position of the pulses is controlled by the algorithm and the width duration in seconds is preset before INIT See Figure 22 Use the following command sequence SOURce FUNCtion RPULse lt ref_channel gt lt ch_list gt to select the channels that will output angular positioned pulses and to specify the reference channel SOURCe RPU
24. Lse WIDTh TIME lt seconds gt lt ch_list gt to preset the pulse width in seconds The algorithm will control the angular pulse position Example of variable position preset width Set up channel 40 as the reference channel and channels 45 through 47 to output variable position pulses RST SENS FUNC RVEL 12 MISS 140 sense rvel for reference channel SOUR FUNC RPULSE 140 145 147 3 rotational pulse output chans SOUR RPULSE WIDT TIME 001 145 14 reset pulse width to 1 millisec Algorithm outputs pulses on all three channels with variable position ALG DEF ALG1 static float Pos1 Pos2 Pos3 0145 Pos1 0146 Pos2 0147 Pos3 ALG SCALAR ALG1 Pos1 60 preset ch 45 s pulse pos to 60 ALG SCALAR ALG1 Pos2 180 preset ch 46 s pulse pos to 180 32 Agilent E1538A Enhanced Frequency Totalize PWM SCP ALG SCALAR ALG1 Pos3 300 ALG UPDATE INIT ALG SCALAR ALG1 Pos1 NewPos1 ALG SCALAR ALG1 Pos2 NewPos2 ALG SCALAR ALG1 Pos3 NewPos3 ALG UPDATE a Index Position pulse width fixed by time before INITiate command A A OOK Qa a 2 0 Gs QZ E extra tooth wheel read by A SENS FUNC RVEL channel pulse position controlled in algorithm by angle ae pulse width fixed by time before INITiate command preset ch 47 s pulse pos to 300 start algorithm execution calculate values for NewPos n later adjust channel 45 s position while algo
25. Messages are 3110 Channel specified is invalid for RVELocity function Note Only one channel on any E1538 SCP can be assigned to the SENS FUNC RVEL function and it must be the first channel on the SCP Inputs read at beginning of each algorithm execution INITiate here Algorithm Executions Signal from Missing Tooth Signal from Extra Tooth l l l l l l 50 50 50 50 Note revolutions not N teeth per second f l l l I I l l I Data to algorithm in RPS 0 Variable Reluctance Sensor a reading extra tooth wheel Figure 14 Sense Rotational Velocity Example of Rotational Velocity Sense Channel 40 senses RVEL and the algorithm reads and returns the velocity value in CVT element 40 RST SENSE FUNC RVEL 12 MISSING 140 12 toothed wheel with one missing from channel 40 ALG DEF ALG1 writecvt I140 40 simply puts value from ch 40 into CVT element 40 INIT start the algorithm loop always will loop from end loop to here SENS DATA CVT 40 query the value from CVT 40 display the RVEL value end loop Agilent E1538A Enhanced Frequency Totalize PWM SCP 23 Prog rammi ng Output This section deals with all aspects of programming output channel functions Channels Channels are configured for output with the I O direction switches see Configuring Input Output direction on page 6 A related error message 3124 E1538 OE switch OFF conflicts with this command Controlli
26. NC RPUL ref_channel gt lt ch_list gt pulse width fixed before SOUR RPUL WIDTh ANGLe lt degrees gt lt ch_list gt INITiate by angle a pulse position controlled varied in algorithm always by angle f SENS FUNC RVEL lt n_teeth gt lt index_type gt lt ref_channel gt SOUR FUNC RPUL lt ref_channel gt lt ch_list gt SOUR RPUL WIDTh TIME lt seconds gt lt ch_list gt A pulse width fixed before INITiate by time pulse position fixed before INITiate always by angle SENS FUNC RVEL lt n_teeth gt lt index_type gt lt ref_channel gt SOUR FUNC RPUL lt ch_list gt lt ch_list gt SOUR RPUL POSition ANGLe lt degrees gt lt ch_list gt SOUR RPUL VARType ANGLe lt ch_list gt A pulse width controlled varied in algorithm by angle pulse position fixed before INITiate always by angle SENS FUNC RVEL lt n_teeth gt lt index_type gt lt ref_channel gt SOUR FUNC RPUL lt ch_list gt lt ch_list gt SOUR RPUL POSition ANGLe lt degrees gt lt ch_list gt SOUR RPUL VARType TIME lt ch_list gt pulse width controlled varied in algorithm by time J A Figure 20 Four Modes of Rotationally Positioned Pulses Agilent E1538A Enhanced Frequency Totalize PWM SCP 29 Rotational Pulse Use SOURce FUNCtion RPULse lt ref_channel gt lt ch_list gt to Command Usage link channels in lt ch_list gt to the rotational pulse function The channel
27. Parameter Range of Default Name Type Values Units per_limit numeric float32 004 to 60 Sec ch_list string 100 163 none Comments lt ch_list gt must be channels on an E1538A SCP Note Although SENS PER LIM UPP can set a timeout period as long as 60 seconds the longest supported periods are 1 second or 4 seconds depending on the setting of SENSe PERiod RANGe e LIMit UPPer period is the maximum time the SCP will allow for any cycle period At any time during the period measurement if the cycle period exceeds Agilent E1538A Enhanced Frequency Totalize PWM SCP 57 the LIMit UPPer period then a period of 0 sec will be returned to the E1415 19 22 algorithm Note A period value of 0 sec is used as a special token that must be tested for in the user s provided 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 period measurement thus preventing the SCP from hanging during measurement In this case typically the upper period limit would be the same as or longer than the APERture time An unusual but valid use is to set the LIMit UPPer period to be less than the APERture period which can provide a means to abort a period measurement if at any point during the measurement the input waveform period is longer than the configured LIMit UPPer Note The upper limit set by SENS PER LIM UPPer is for a single signal period
28. R RPULSE POS ANGL 140 146 preset channel 46 pulse position to 140 degrees SOUR RPULSE POS ANGL 260 147 preset channel 47 pulse position to 260 degrees SOUR RPULSE VART ANGL 1 45 1 47 algorithm will control pulse width by ANGLE Algorithm outputs pulses on all three channels with variable width ALG DEF ALG1 static float Width1 Width2 Width3 0145 Width1 0146 Width2 0147 Width3 ALG SCALAR ALG1 Width1 5 preset ch 45 s pulse width to 5 ALG SCALAR ALG1 Width2 10 preset ch 46 s pulse width to 10 ALG SCALAR ALG1 Width3 15 preset ch 47 s pulse width to 15 ALG UPDATE INIT start algorithm execution calculate NewWidth n ALG SCALAR ALG1 Width1 NewWidth1 later adjust channel 45 s width while algorithm is running ALG SCALAR ALG1 Width2 NewWidth2 later adjust channel 46 s width while algorithm is running ALG SCALAR ALG1 Width3 NewWidth3 later adjust channel 47 s width while algorithm is running ALG UPDATE 34 Agilent E1538A Enhanced Frequency Totalize PWM SCP R ie 4 EROR z Wg Index Position 10 degrees algorithm controlled pulse width by angle NN oN rae extra tooth wheel read by _ SENS FUNC RVEL channel algorithm controlled pulse width by angle asind p xy A algorithm controlled pulse width by angle Figure 23 Fixed Position Variable Width by Angle Rotational Pulse Mode Variable Pulse Wid
29. URce FM STATe ON OFF lt ch_list gt 63 SOURce FM STATe lt channel gt 64 SOURce PULSe WIDTh lt width gt lt ch_list gt 71 SOURce PULSe WIDTh lt channel gt 72 SOURce PULM STATe ON OFF lt ch_list gt 69 SOURce PULM STATe lt channel gt 70 SOURce PULSe PERiod lt period gt lt ch_list gt 70 SOURce PULSe PERiod lt channel gt 71 SOURce FUNCtion SHAPe SQUare lt ch_list gt 67 SOURce FM STATe ON OFF lt ch_list gt 63 SOURce FM STATe lt channel gt 64 SOURce FUNCtion STEPper lt preset_pos gt lt mode gt lt min_vel gt lt max_vel gt lt ch_list gt 67 SYSTem CTYPe lt channel gt 12 Agilent E1538A Enhanced Frequency Totalize PWM SCP 43 INPut POLarity INPut POLarity lt mode gt lt ch_list gt sets logical input polarity on a digital SCP channel Parameters Parameter Parameter Range of Default Name Type Values Units mode discrete string NORMal INVerted none ch_list string 100 163 none Comments e If the channels specified are on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual to determine its capabilities Related Commands for output sense SOURce PULSe POLarity e RST Condition INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpel4XX_cmd Usage _INP POL INV 140 143 invert first 4 chann
30. _vel and max_vel Four phase stepper motors that require less than 100mA phase current 68 Agilent E1538A Enhanced Frequency Totalize PWM SCP can be directly driven by the SCP See Figure 29 for a connection diagram that also shows the required user supplied output protection components lt ch_list gt specifies the channels that will control stepper motors The channels referenced can be on more than one E1538 The channels must be in ascending order Based on the lt mode gt parameter the channels will be arranged into adjacent groups of 2 C2 or 4 C4 channels These groups can not be split across SCPs The algorithm can send new position values to the first channel in a motor group The algorithm will read the current position value from the second channel in the motor group Related error messages 3115 Channels specified are not in ascending order 3116 Multiple channels specified are not grouped correctly 3117 Grouped channels are not adjacent Send with VXIplug amp play Function hpel14XX_cmd Usage See Stepper Motor Control on page 37 preset count to 0 full step half speed 4 channel min speed 64s s max speed 256s s in half speed mode actual speed half specified speed SOUR FUNC STEP 0 MFSFC4 128 512 144 147 SOURce PULM STATe 1SOURce PULM STATe lt enable gt lt ch_list gt enable the pulse width modulated mode for the PULSe channels in lt ch_list gt
31. anges in rotational velocity will not change the time proportion of the pulse Of course changes in rotational velocity do effect the angular proportion of the pulse Usage SOUR RPULSE WIDT TIME 0040 1 47 preset channel 47 pulse width to 4 mSec Agilent E1538A Enhanced Frequency Totalize PWM SCP 75 SOURce RPULse WIDTh TIME SOURce RPULse WIDTh TIME lt channeb returns the width of the rotational output pulse currently set for lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must specify a single channel only Usage SOUR RPULSE WIDT TIME 1 47 return the pulse width set for channel 47 76 Agilent E1538A Enhanced Frequency Totalize PWM SCP Specifications These specifications for the E1538A reflect its performance while installed on your VXI module General Specifications Output Characteristics Characteristic Pull Up Off Pull Up On 10K to Vcc current source logic 1 0 38mA 1 2V current sink logic 0 100 mA 100 mA Voltage logic 1 0 5V no load Voltage logic 0 0 5 Max sinking 100mA 0 5 Max sinking 100mA 0 1 Max sinking 20mA 0 1 Max sinking 20mA Input Characteristics Characteristic Pull Up Off Pull Up On 10K to Vcc VRS OFF for Chs0 amp 1 Equivalent circuit 120K conn to O Volts 9 2KQ conn to 4 6 Volts Maximum input low programmable from programma
32. aried by the algorithm Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt ch_list gt must specify a single channel only Returns the string TIME ANGL Usage SOUR RPULSE VART 145 returns the setting for chan 45 SOURce RPULse WIDTh ANGLe SOURce RPULse WIDTh ANGLe lt degrees gt lt ch_list gt sets the width of the rotational output pulse before the INIT command that starts algorithm execution With the pulse width thus fixed the pulse position in angle or time depending on how SOUR RPUL VARType is set will be controlled by the algorithm Parameters Parameter Parameter Range of Default Name Type Values Units degrees numeric uint32 0t0360 degrees ch_list string 100 163 none Comments Channels in lt ch_list gt must be referenced in a SOUR FUNC RPUL command before the next INIT command Related error messages 3113 Channel specified is not in same SCP as reference channel 3114 First channel in SCP can not be used in RPULse output channel list lt degrees gt has a resolution of 1 degree Since the pulse width is specified in angle changes in rotational velocity will not change the angular proportoin of the pulse Of course changes in rotational velocity do effect the pulse width as regards time Usage SOUR RPULSE WIDT ANGL 260 1 47 preset channe
33. ble from 46 to 46 Volts 0 5V 46 to 46 Volts 0 5V Minimum input high Input Isolation No Isolation Provided Cross Talk Between Channels A large signal on one channel has an effect on the accuracy of frequency measured on other channels as follows Sine wave interfering signal up to 70Vpp No degradation of specification Square wave Interfering signal lt 63Vpp No degradation of specification Square wave Interfering signal gt 63Vpp to Minimum input amplitude changes from 15mV 70Vpp to 18mV for frequency range of 1Hz to 10Khz see Input Signal Characteristics spec Maximum voltage applied to any 48 Volts to 48 Volts input terminal Maximum voltage applied to any 0 48 Volts outputs are diode clamped at 0 3V output terminal Agilent E1538A Enhanced Frequency Totalize PWM SCP 77 Totalizer Capacity 24 bits or 16 777 215 Minimum Pulse Width 500nS Frequency Range 0 100 KHz M remen Gate Time t Frequency Measurement taperture 1 mSec to 1 Second resolution i Range 3 to 100 000 aperture Accuracy 01 Resolution Hz fa lapertire 4 194MHz Minimum Pulse Width 500 nS Period Measurement Gate Time taperture 40 Sec to 4 Second Range SENS PER RANGE 1 10uSec to lagarpiee 1 sec max SENS PER RANGE 4 40uSec tO taperrure 4 Sec max Accuracy 01 Resolution 2384uSec Minimum Pulse Width 500 nSec Time out Mechanism Programmable 4mSec to 60Sec SENS FREQ LIM LOW amp S
34. d channels have individually programmable threshold levels that can range from 46V to 46V Identifying the Plug on IMPORTANT There are two versions of the E1538A The early version does not support a PERiod measurement command set Early versions have ROM revision February 1998 and earlier The later version adds period measurement and an improved frequency measurement function The later versions have ROM revision after February 1998 In order to access the additional functions of the later E1538A you must use one of the following drivers The Plug amp Play driver with revision A 02 07 or later The Command Module driver with revision A 05 11 or later To determine the driver revision execute the IDN command Board Viewed With Connectors Behind fa eS Et E1538 88811 For Model ID look for E1538 prefix on ROMs New ROMs with Period Measurement have date codes later than Feb 98 Figure 1 Identifying the SCP and its ROM Revision Agilent E1538A Enhanced Frequency Totalize PWM SCP 5 Setting Configuration Switches The SCP has three packages of eight switches each The package labeled OE Output Enable determines a channel s I O direction The package labeled PU pull up controls whether or not a channel is floating or pulled up to an internal 5V supply The package labeled VRS for channels 0 and 1 only can enable special input signal conditioning c
35. ds lt count gt lt ch_list gt X 60 SENSe PERiod NPERiods lt channel gt X 61 SENSe PERiod RANGe UPPer lt count gt lt ch_list gt X 61 SENSe PERiod RANGe UPPer lt channel gt X 62 SENSe FUNCtion PWIDth lt avg_count gt lt ch_list gt 52 SENSe FUNCtion QUADrature lt preset_count gt lt ch_list gt 32 SENSe FUNCtion RVELocity lt n_teeth gt lt index_type gt lt ch_list gt 53 SENSe FUNCtion TOTalize lt ch_list gt 55 SENSe TOTalize RESet MODE INIT TRIG lt ch_list gt 62 42 Agilent E1538A Enhanced Frequency Totalize PWM SCP Table 2 Command Syntax For newer Page units only Discussed SENSe TOTalize RESet MODE lt channel gt 63 OUTPut POLarity NORM INV lt ch_list gt 46 OUTPut POLarity lt channel gt 46 SOURce FUNCtion RPULse lt ref_chan lt ch_list gt 65 SOURce RPULse POSition ANGLe lt degrees gt lt ch_list gt 72 SOURce RPULse POSition ANGLe lt channel gt 73 SOURce RPULse WIDTh ANGLe lt degrees gt lt ch_list gt 74 SOURce RPULse WIDTh ANGLe lt channel gt TS SOURce RPULse WIDTh TIME lt seconds gt lt ch_list gt 75 SOURce RPULse WIDTh TIME lt channel gt 76 SOURce RPULse VARType ANGLe TIME lt ch_list gt T3 SOURce RPULse VARType lt channel gt 74 SOURce FUNCtion SHAPe CONDition lt ch_list gt 66 SOURce FUNCtion SHAPe PULSe lt ch_list gt 66 SO
36. dule use the SYSTem CTYPe lt channel gt command The channel parameter specifies a single channel in the channel range covered by the SCP of interest The first channel number for each of the eight SCP positions are 0 8 16 24 32 40 48 and 56 The value returned for the E1538A SCP is HEWLETT PACKARD E1538A Enhanced Frequency Totalize PWM SCP 0 0 To determine the type of SCP installed on channels 0 through 7 send SYST CTYPE 100 query SCP type chO enter statement here enter response string The E1538A has eight digital channels The Power on and RST state is that all input configured channels sense static digital state SENS FUNC COND and all output configured channels output static digital state SOUR FUNC COND Logical sense is normal INP POL NORM and OUTP POL NORM Channels are configured for input or output with the I O direction switches see Setting Configuration Switches on page 6 This section deals with all aspects of programming input channel functions Channels are configured for input with the I O direction switches see Configuring Input Output direction on page 6 A related error message 3123 E1538 OE switch ON conflicts with this command The E1538 allows programmatically setting the input threshold level for each input configured channel The input threshold can be set from 46VDC to 46VDC with 375V resolution While input polarity is set to NORMAL an input level higher than the thresho
37. e algorithm can now output a frequency value to channel 45 0145 250 channel 45 will source 250 Hz pulse train Output changes only at the end of each algorithm execution My Ta in 7 INITiate here Algorithm Executions Mo No Y N O Algorithm data to 100 200 400 500 output channel gt la 100Hz 10mS gt 200Hz 5mS gt 400Hz 2 5mS la 500Hz i I i Signal at Output Channel i LTT 100 Preset Pulse Width gt a 2mS 20 gt a 2mS 40 gt a 2mS 80 Figure 18 Output Fixed Pulse Width Variable Frequency FM Agilent E1538A Enhanced Frequency Totalize PWM SCP 27 Variable Frequency This means that the E1538 outputs a continuous train of pulses whose Square Wave Pulse Train frequency is controlled by the algorithm The the duty cycle of the waveform FM is always 50 Use the following command sequence SOURce FUNCtion SQUare lt ch_list gt to enable square wave generation SOURce FM STATe ON lt ch_list gt to select the FM mode The frequency value sent by the algorithm can range from 64Hz to 40KHz 2 fout The frequency resolution is TIAM To configure channel 45 to output variable frequency continuous train with 50 duty cycle square wave SOUR FUNC SQUARE 145 channel sources square wave SOUR FM ON 145 and continuous PWM train The algorithm can now output a
38. e average is complete are from a single period measurement Average signal periods for pe APERI re Or NPE Rds for one second or 1000 periods Figure 11 Input Period 18 Agilent E1538A Enhanced Frequency Totalize PWM SCP SCP averages signal periods in these examples To measure period at channel 45 as the average of 1000 signal periods RST TRIGGER TIMER 2 SENS FUNC PER 145 SENS PER RANGE 1 145 SENS PER MODE NPER 145 SENS PER NPER 1000 145 ALG DEF ALG1 writecvt 1145 45 INIT do loop SENS DATA CVT 45 read value from CVT query above end loop Alg executes at 2 sec intervals ch 45 to measure signal period set period range 10sec Isec set meas interval by n periods meas and avg 1000 sig periods alg puts period in CVT start algorithm execution get period from CVT Agilent E1538A Enhanced Frequency Totalize PWM SCP 19 Measure Pulse Width Data received at beginning of each This means that the E1538 will measure the width of the logic 1 portion of a pulse The pulse width is sent to the algorithm in units of seconds To measure the high portion of a pulse positive going edge to negative going edge set the channel input polarity to INP POL NORM lt ch_list gt To measure the low portion of the pulse negative going edge to positive going edge set the channel input polarity to INP POL INV lt ch_list gt The value returned to an algorithm can be from 5uSec to 1 S
39. easure Pulse Width 0 00000 page 20 Sense Quadrature Position page 21 Sense Rotational Velocity 0 page 22 Programming Output Channels page 24 Controlling Output Polarity page 24 Output Static Digital State 2 2 ee page 24 Variable Width Pulse Per Trigger page 25 Variable Width Pulse Train PWM page 26 Variable Frequency Fixed Width Pulse Train FM page 27 Variable Frequency Square Wave Pulse Train FM page 28 Rotationally Positioned Pulse Output page 29 Rotational Pulse Command Usage page 30 Stepper Motor Control 2 0 02 0 000000 eee page 37 RST and TST important 00 page 41 SCPI Command Reference 004 page 42 Specifications ee ee bee ce ne ee ee page 77 Agilent E1538A Enhanced Frequency Totalize PWM SCP 3 Introduction The Agilent E1538A provides eight TTL compatible channels of digital I O Channels can be individually configured to perform any one of the following functions e Input Static digital state Frequency measurement Period meaurement Totalize positive or negative signal transitions Pulse width measurement Rotational velocity senses added or missing cogwheel teeth Quadrature position requires 2 channels Ou
40. easurement resolution in seconds is fixed while the relative resolution as a percentage of the input signal period is variable That is when NPERiods is set to provide an adequate resolution for short period signals long period signals will have increased resolution 2 The APERture mode sets a fixed duration that the SCP will use to measure multiple signal periods The actual effective APERture lt time gt will be lt time gt x signal_period Feat eaioa eek ry The minimum aperture will be 1 signal period and the maximum will be 255 signal periods In APERture mode the effective resolution in seconds varies with the period of the input signal That is as the signal period is reduced the number of measurements averaged increases thereby improving the effective resolution However the relative resolution as a percentage of the input signal period is fairly constant with changes in signal period Generally more measurements greater NPERiod count or longer APERture time means a more accurate frequency value Of course more measurements means that the reading returned contains more latency is older in relation to the signal s current frequency To track fast changing frequency you have to trade off some accuracy with a shorter aperture time 16 Agilent E1538A Enhanced Frequency Totalize PWM SCP Measure Frequency Frequency read at the beginning of each Use SENSe FREQuency APERture lt time gt l
41. econd with 59 6nSec resolution To configure channels to measure pulse width use the command SENSe FUNCtion PWIDth lt avg_count gt lt ch_list gt e lt avg_count gt sets the number of pulses to average when forming the pulse duration value More counts give more accurate readings but slower response to changing pulse widths lt ch_list gt specifies the channels that will read pulse widths To measure pulse width on channels 46 amp 47 RST SENS FUNC PWID 4 146 147 read puls width on chs 46 amp 47 Algorithm reads the pulse widths on channels 146 and 147 and returns these values in CVT elements 46 and 47 ALG DEF ALG1 writecvt 1146 46 writecvt 1147 47 INIT start algorithm SENS DATA CVT 46 47 read pulse widths from CVT algorithm execution INITiate here Algorithm Executions Pp E gt A 105mS lt avg_count gt example p l average of 4 pulses l l l i l 1 i 7 Width as Read by Algorithm 0 assumes polarity is normal 0 0 105 0 105 Figure 12 Measure Pulse Width 20 Agilent E1538A Enhanced Frequency Totalize PWM SCP Sense Quadrature Position This means that the E1538 will convert a digital quadrature signal pair into an absolute 24 bit count The count value can be read by the algorithm The E1538 s quadrature position function increments a counter value each time there is a transition on either of the quadrature channel pair When t
42. ecution INITiate here This means that the channel generates a pulse whose width is specified by the algorithm each time the algorithm executes The value sent by the algorithm can range from 7 87uSec to 7 812mSec The command sequence to set up this mode is SOURce FUNCtion PULSe lt ch_list gt to enable pulse generation the following two commands return the E1538 to the Single pulse per trigger mode from either the FM or Pulse Width Modulation modes Since Single pulse per trigger is the default pulse mode at power up or after RST only RST then SOUR FUNC PULS lt ch_list gt are actually needed SOURce FM STATe OFF lt ch_list gt to disable FM mode SOURce PULM STATe OFF lt ch_list gt to disable PWM mode To configure channel 44 to output a single controlled width pulse per trigger RST after RST sour func puls is all that is required to enable the default single pulse per trigger mode SOUR FUNC PULS 144 channel sources pulses ALG DEF ALG1 static float outpulse 0 001 0144 outpulse INIT start alg execution ALG SCAL ALG1 outpulse 5E 4 Sms pulse ALG UPDATE N i 400ms gt i i i Algorithm Executions Bel j a f a Algorithm data to 0 06 output channel gt lt 60mS 350mS _ 4 180mS 20mS gt lt i l 0 35 0 18 0 02 l l l Signal at Output Channel Fig
43. els on SCP at SCP position 5 Channels 40 through 43 INPut POLarity INPut POLarity lt channel gt returns the logical input polarity on a digital SCP channel Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must specify a single channel e If the channel specified is on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual to determine its capabilities Returned Value returns NORM or INV The type is string Send with VXIplug amp play Function hpe14XX_cmdString_Q 44 Agilent E1538A Enhanced Frequency Totalize PWM SCP INPut THReshold LEVel INPut THReshold LEVel lt eveb lt ch_list gt allows programmatically setting the input threshold level for each input configured channel Parameters Parameter Parameter Range of Default Name Type Values Units level numeric float32 46 VDC to 46 VDC none ch_list string 100 163 none Comments e lt level gt can be set to a resolution of 375V e While input polarity is set to NORMAL an input level higher than the threshold level is considered a logic one and an input level lower than the threshold level is considered a logic zero If input polarity is set to INVerted an input level higher than the threshold level is considered a logic zero and an input level lower than the threshold level i
44. et the interval for measuring and averaging signal periods For PERiod function the E1538 spports two distinct measurement ranges 1 When SENS PER RANGE is set to lsec the E1538 can measure periods from 10usec Isec The value of SENS PER APER can range from 10usec lsec 2 When SENS PER RANGE is set to 4sec the E1538 can measure periods from 40usec 4sec The value of SENS PER APER can range from 40usec 4sec See SENS PER RANGE command on page 61 Use SENSe FUNCtion PERiod lt ch_list gt to configure channels to measure signal period To measure the signal period at channel 45 with aperture of 01 second RST TRIGGER TIMER 2 SENS FUNC PER 145 SENS PER RANGE 1 145 SENS PER MODE APER 145 SENS PER APER 1 145 ALG DEF ALG1 writecvt l145 45 INIT do loop SENS DATA CVT 45 read value from CVT query above end loop Period read at the beginning of each Alg executes at 2 sec intervals ch 45 to measure signal period set period range 10 Usec Isec set meas and avg interval mode meas and avg sig periods for 1S alg puts period in CVT start algorithm execution get period from CVT INITiate here 2Sec gt algorithm execution Ne QO a Algorithm Executions set by TRIG TIMER Signal at Input Channel 1KHz l l Period Value Read by Algorithm 998e 3 998e 3 998e 3 998e 3 All values returned befor
45. float32 Send with VXIplug amp play Function hpe14XX_cmdReal64_Q SOURce RPULse POSition ANGLe SOURce RPULse POSition ANGLe lt degrees gt lt ch_list gt sets the angular position of the rotational output pulse before the INIT command that starts algorithm execution With the pulse position thus fixed the pulse width in angle or time depending on how SOUR RPUL VARType is set will be controlled by the algorithm Parameters Parameter Parameter Range of Default Name Type Values Units degrees numeric int32 33 5954 430 to 33 554 430 degrees ch_list string 100 163 none Comments Channels in lt ch_list gt must be referenced in a SOUR FUNC RPUL command before the next INIT command Related error messages 3113 Channel specified is not in same SCP as reference channel 3114 First channel in SCP can not be used in RPULse output channel list e lt degrees gt has a resolution of 1 degree The pulse is positioned at lt degrees gt modulo 360 72 Agilent E1538A Enhanced Frequency Totalize PWM SCP Usage SOUR RPULSE POS ANGL 20 145 preset channel 45 pulse position to 20 degrees SOURce RPULse POSition ANGLe SOURce RPULse POSition ANGLe lt channel gt returns the angular position set for lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comme
46. frequency value to channel 45 0145 2000 channel 45 will source 2 KHz square wave Output changes only at the end of each algorithm execution a y s INITiate here Algorithm Executions noo Moo YO o Algorithm data to 100 200 400 500 output channel Hz i gt la 100Hz 10mS gt a 200Hz 5mS la 400Hz 2 5mS 4 500Hz 2mS Signal at Output Channel bed Il Pulse Width period 2 gt la 5mS 50 gt a 2 5mS 50 gt lt 1mS 50 Figure 19 Output Square Wave Variable Frequency FM 28 Agilent E1538A Enhanced Frequency Totalize PWM SCP Rotationally Positioned This means that the E1538 will generate pulses which are positioned by angle Pulse Output usually shaft angle The rotational pulse function requires a rotational reference and this is provided by the SENS RVEL function from the SCP s first channel There are four related commands that set up rotational pulses Combinations of these commands can set up four different rotational pulse modes Figure 20 shows these modes and the command sequence for each Following Figure 20 is the command reference for all four commands Following that are examples of each of the four modes D aiie property pulse position controlled varied in algorithm always by angle y fixed property Q angle At time SENS FUNC RVEL lt n_teeth gt lt index_type gt lt ref_channel gt SOUR FU
47. h_list gt sets the fixed pulse width value on the frequency modulated pulse channels in lt ch_list gt Parameters Parameter Parameter Range of Default Name Type Values Units pulse_width numeric float32 7 87E 6 to 7 8125E 3 seconds 238 4E 9 resolution ch_list string 100 163 none Comments e If the channels specified are not on a Frequency Totalize SCP an error will be generated RST Condition SOUR FM STATE OFF and SOUR PULM STATE OFF e Related Commands SOUR PULM STATE SOUR PULS POLarity The variable frequency control for this channel is provided by the algorithm language When the algorithm executes an assignment statement to this channel the value assigned will be the frequency setting For example 0143 2000 set channel 43 to 2KHz Agilent E1538A Enhanced Frequency Totalize PWM SCP 71 Send with VXIplug amp play Function hpel4XX_cmd Usage SOUR PULS WIDTH 2 50E 3 143 set fixed pulse width of 2 5 msec on channel 43 SOURce PULSe WIDTh SOURce PULSe WIDTh lt ch_list gt returns the fixed pulse width value on a frequency modulated pulse channel Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments Channel must specify a single channel e If the channels specified are not on a Frequency Totalize SCP an error will be generated e Returned Value returns the numeric pulse width The type is
48. he lower numbered channel s signal LEADS the higher numbered channel the function counts up When the lower numbered channel LAGS the higher numbered channel the function counts down To configure a pair of channels to sense quadrature count use SENSe FUNCtion QUADrature lt count_preset gt lt ch_list gt lt count_preset gt if included allows presetting the absolute counter associated with the channel pair All quadrature pairs in lt ch_list gt will be preset to the same value If not included the default count at algorithm start will be zero lt count_preset gt can range from 0 to 16 777 215 The variable type is int32 lt ch_list gt must always specify both channels of a pair More than one pair can be specified Both channels of any pair must be adjacent lt ch_list gt can specify channels on more than one E1538 The channel numbers in lt ch_list gt must be in ascending order The related error messages are 3115 Channels specified are not in ascending order 3116 Multiple channels specified are not grouped correctly 3117 Grouped channels are not adjacent 3122 This multiple channel function must not span multiple SCPs The algorithm reads the current count through the low numbered channel The count is an unsigned 24 bit value ranging from 0 to 16 777 215 The counter can roll over from 16 777 2215 to 0 and roll under from 0 to 16 777 215 is 16 777 215 To configure channels 42 and 43 as o
49. he channels specified as digital inputs See About Period and Frequency Measurements on page 16 Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Comments e If the channels specified are on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual for its capabilities Related commands SENS FREQ APER SENS FREQ MODE e RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpel14XX_cmd Usage See About Period and Frequency Measurements on page 16 SENS FUNC FREQ 144 SENSe FUNCtion PERiod SENSe FUNCtion PERiod lt ch_list gt sets the SENSe function to period for channels in lt ch_list gt Also configures the channels specified as digital inputs See About Period and Frequency Measurements on page 16 Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Comments e If the channels specified are on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual for its capabilities Related commands SENS PER APER SENS PER NPER Agilent E1538A Enhanced Frequency Totalize PWM SCP 51 SENS PER MODE RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channe
50. ia Ss Bn i DE in Signal at Input Channel Data Received in Algorithm change ignored change ignored Data Latency Examples gt Figure 8 Input Static Digital States 14 Agilent E1538A Enhanced Frequency Totalize PWM SCP A Count as Read by Algorithm 0 assumes polarity is normal B Count as Read by Algorithm 0 Totalize Positive or Negative Edge State Changes Totalize count reset and restarted at each Use SENSe FUNCtion TOTalize lt ch_list gt to configure channels to totalize Totalize means to simply count state transitions either positive going or negative going Figure 9 A shows totalizing transitions between each algorithm execution Figure 9 B shows totalizing all transitions starting from the time the module last received an INITiate command Use SENSe TOTalize RESet MODe INIT TRIG lt ch_list gt to configure the totalize channel to either reset its count once each trigger event or only when the module is INITiated Use INP POL INV to sense negative edges The count capacity is 16 777 215 24 bits unsigned To totalize state changes at channel 44 starting from INITiate time RST SENS TOT RES MOD INIT 144 SENS FUNC TOT 144 ALG DEF ALG1 writecvt 1144 44 INIT ch 44 totalize reset at INIT ch 44 is totalize input alg sends count to CVT SENS DATA CVT 44 get totalize count from cvt SENSe TOTalize RESet MODe TRIG algorith
51. igure 25 Relationship of min_vel and max_vel lt ch_list gt specifies the channels that will control stepper motors A Agilent E1538A Enhanced Frequency Totalize PWM SCP 37 motor phase channel group can not be split across SCPs The algorithm sends new position values to the first channel in a motor group The algorithm reads the current position value from the second channel in the motor group Example of full step full speed 4 phase stepper motor operation RST preset count to 0 full step half speed 4 channel min speed 64s s max speed 256s s in half speed mode actual speed half specified speed SOUR FUNC STEP 0 MFSFC4 128 512 144 147 SENS FUNC VOLT 100 channel 0 reads voltage Algorithm reads voltage a t channel 00 multiplies it by 100 to derive the value to send to the motor Only when the expected motor position previously sent to ch44 and the actual motor position read from ch45 agree is anew motor position is sent to ch44 ALG DEF ALG1 static float MotorDrive MotorDrive 1100 100 512 5 12V 0 MtrDrv If 0144 1145 0144 MotorDrive INIT start algorithm The following figures show the step waveforms for the five built in step modes 2 Phase Bipolar Stepper Motor SCP Channel n 0 6 m Algorithm sends position i value to this channel H bridge SCP Channel n 1 Drivers Algorithm reads position ee ill value from this channel 4
52. in lt ref_channel gt will be linked to the SENS FUNC RVEL function to provide the rotational reference information to SOUR FUNC RPUL The commands SOURce RPULse POSition ANGLe lt degrees gt lt ch_list gt SOURce RPULse WIDTh ANGLe lt degrees gt lt ch_list gt and SOURce RPULse WIDTh TIME lt seconds gt lt ch_list gt fix the channels rotational pulse position SOUR RPUL POS ANGL or the rotational pulse width SOUR RPUL WIDT ANGL and TIME before the INITiate command The remaining pulse property the property NOT specified in one of these commands will be controlled within the algorithm lt ch_list gt specifies the SOUR FUNC RPUL channel s that will be set to the property specified by the command syntax For pulse position lt degrees gt can range from 33 554 430 to 33 554 430 degrees with a resolution of 1 degree The pulse is positioned at lt degrees gt modulo 360 For pulse width lt degrees gt can range from 0 to 360 degrees with a resolution of 1 degree e lt time gt specifies pulse width in seconds ranging from 00000787 7 87 US to 015624 15 624mS with a resolution of 238 4nS The command SOUR RPULse VARType ANGLe TIME lt ch_list gt specifies the type of value that will be controlled varied by the algorithm e ANGLe specifies that the algorithm will send values of angle in degrees to the channel s TIME specifies that the algorithm will send values of
53. l 47 pulse width to 74 Agilent E1538A Enhanced Frequency Totalize PWM SCP 260 degrees SOURce RPULse WIDTh ANGLe SOURce RPULse WIDTh ANGLe lt channel gt returns the width of the rotational output pulse currently set for lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must specify a single channel only Usage SOUR RPULSE WIDT ANGL 147 return pulse width for channel 47 SOURce RPULse WIDTh TIME SOURce RPULse WIDTh TIME lt seconds gt lt ch_list gt sets the width of the rotational output pulse before the INIT command that starts algorithm execution With the pulse width thus fixed the pulse position in angle or time depending on how SOUR RPUL VARType is set will be controlled by the algorithm Parameters Parameter Parameter Range of Default Name Type Values Units seconds numeric int32 00000787 to 015624 seconds ch_list string 100 163 none Comments Channels in lt ch_list gt must be referenced in a SOUR FUNC RPUL command before the next INIT command Related error messages 3113 Channel specified is not in same SCP as reference channel 3114 First channel in SCP can not be used in RPULse output channel list e lt seconds gt specifies pulse width in seconds with a resolution of 238 4nS e Since the pulse width is specified in seconds ch
54. l three channels with preset duration ALG DEF ALG1 static float Width1 Width2 Width3 0145 Width1 0146 Width2 0147 Width3 ALG SCALAR ALG1 Width1 005 ALG SCALAR ALG1 Width2 010 ALG SCALAR ALG1 Width3 015 ALG UPDATE INIT ALG SCALAR ALG1 Width1 NewWidth1 ALG SCALAR ALG1 Width2 NewWidth2 ALG SCALAR ALG1 Width3 NewWidth3 ALG UPDATE e S oO ae ws K se 4 nos oo Index Position 0 degrees preset ch 45 pulse width to 5ms preset ch 46 pulse width to 10ms preset ch 47 pulse width to 15ms start algorithm execution calculate NewWidth n later adjust channel 45 s width while algorithm is running later adjust channel 46 s width while algorithm is running later adjust channel 47 s width while algorithm is running values in update queue sent to variables extra tooth wheel read by _ SENS FUNC RVEL channel algorithm controlled lt pulse width by time X D Q th 2 KA a Sy Se Ke algorithm controlled pulse width by time Figure 24 Fixed Position Variable Width by Time 36 Agilent E1538A Enhanced Frequency Totalize PWM SCP Stepper Motor Control lt max_vel gt steps second lt min_vel gt steps second pee ees es ee ee ee Use the command SOURce FUNCtion STEPper lt preset_pos gt lt mode gt lt max_vel gt lt min_vel gt lt ch_list gt to control stepper motors
55. ld level is considered a logic one and an input level lower than the threshold level is considered a logic zero If input polarity is set to INVerted an input level higher than the threshold level is considered a logic zero and an input level lower than the threshold level is considered a logic one To set input threshold level use the command INPut THReshold LEVel lt level gt lt ch_list gt e lt evel gt is a value between 46 and 46 inclusive The resolution for lt level gt is 0 375 Volts The RST and power on default for lt evel gt is 1 78 volts The value sent for lt evel gt will be rounded to the nearest multiple of 0 375 Volts For instance 5 would be 4 875 10 would be 10 125 9 5 would be 9 375 and 15 would be 15 The INP THR LEV query will return the actual setting 12 Agilent E1538A Enhanced Frequency Totalize PWM SCP Channels in lt ch_list gt must be input configured channels Determining the Input To determine a channel s input threshold level use the command Threshold Level INPut THReshold LEVel lt channel gt Note Because the E1538 rounds lt evel gt to the nearest multiple of 0 375 the returned value can be different from the value sent lt channel gt must specify a single input configured channel INP THR LEV returns a numeric value between 46 and 46 The C SCPI type is int32 To query the threshold level on the second channel at SCP position 4 send INP
56. le channel e If the channel specified is not on a Frequency Totalize SCP an error will be generated Returned Value returns 1 ON or 0 OFF The type is uint16 Send with VXIplug amp play Function hpel14XX_cmdInt16_Q 64 Agilent E1538A Enhanced Frequency Totalize PWM SCP SOURce FUNCtion RPULSe SOURce FUNCtion RPULse lt ref_channel gt lt ch_list gt links channels in lt ch_list gt to the rotational pulse function The channel in lt ref_channel gt will be linked to the SENS FUNC RVEL function to provide the rotational reference information to SOUR FUNC RPUL Parameters Parameter Name ref_channel Parameter Range of Default Type Values Units string 100 108 116 124 132 140 148 156 none ch_list string 100 163 none Comments e lt ref_channel gt must be a single channel and must be the first channel on the SCP The channel specified in lt ref_channel gt must be linked to the SENS FUNC RVEL function before the INIT command is received See page 22 for more on RVEL The related error messages are 3111 multiple channels are specified in reference channel list 3112 Channel specified is invalid for RPULse reference channel 3119 RPULse reference channel must be defined as RVELocity type Channels in lt ch_list gt must be higher numbered and on the same SCP as the channel specified in lt ref_channel gt The related error messages are
57. locks __ or connectors Output Configured HP E1538 Channel output configured channel Dig Gnd OV shielded twisted pair E1415 19 s analog ground common to all channels use guard to _ For output configured channels Hnn R ground jumper z MUST NOT BE DRIVEN BELOW Lnn or a diode that is part of the output transistor will conduct heavily HP E1415 19 s Chassis Ground Figure 5 Recommended Connections and Voltage Limits Input and Output Characteristics Input Characteristics This section describes the E1538 s channel input and output electrical characteristics Refer to Figure 6 for the following discussions When configured for input E1538 channels provide digital input through the threshold comparator The digital input threshold level is programmable with a SCPI command from 48 to 47 625 VDC in 375V steps relative to the Lnn terminal The threshold amplifier also provides typically 0 5 volts of hysteresis regardless of the threshold level setting The input impedance in this configuration is greater than 100KQ as long as the 10KQ pull up resistor is OFF Channels 0 and 1 also provide the capability when the VRS switch is ON to read the output of variable reluctance sensors Because the output of a VRS varies in relation to the velocity of the toothed wheel it is reading the E1538A provides adaptive amplifiers for these channels The function of the amplifier Agilent E1538A Enhanced Fre
58. ls Send with VXIplug amp play Function hpel14XX_cmd Usage See About Period and Frequency Measurements on page 16 SENS FUNC PER 144 SENSe FUNCtion PWIDth SENSe FUNCtion PWIDth lt avg_count gt lt ch_list gt configures channels to measure the input signal pulse width See Measure Pulse Width on page 20 Parameters Parameter Parameter Range of Default Name Type Values Units avg_count numeric uint32 1 to 255 MINimum MAXimum seconds ch_list string 100 163 none Comments e lt ch_list gt must be channels on an E1538A SCP lt avg_count gt sets the number of pulses to average when forming the pulse duration value More counts give more accurate readings but slower response to changing pulse widths e RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpel4XX_cmd Usage See Measure Pulse Width on page 20 SENS FUNC PWID 10 146 147 channels 46 amp 47 meas pulse width SENSe FUNCtion QUADrature SENSe FUNCtion QUADrature lt preset_count gt lt ch_list gt configures a pair of E1538 channels to measure quadrature count See Sense Quadrature Position on page 21 52 Agilent E1538A Enhanced Frequency Totalize PWM SCP Parameters Parameter Parameter Range of Default Name Type Values Units preset_count numeric int32
59. m trigger TRR INITiate here Algorithm Executions Signal at Input Channel Totalize count reset only when module receives INITiate INITialize Here Algorithm Executions Signal at Input Channel assumes polarity is normal a a a S E KE ee 9 Dene eee ee l l l l l l l l l l i l l l l l l l l l l l i l i l l i i i i i i 3 2 3 2 3 2 SENSe TOTalize RESet MODe INIT Figure 9 Input Totalize Count Agilent E1538A Enhanced Frequency Totalize PWM SCP 15 About Period and The E1538A actually measures signal period for both the period and Frequency frequency functions If the measurement function is set to frequency rather Measurements than period the SCP returns the reciprocal of the measured period The resolution of each period measurement is based on the time processor chip s timer period 238 4nS To improve resolution on faster input signals multiple signal periods can be measured and averaged For period measurements there are two different modes that can be used to control the number of periods to average For frequency measurements only the APERture mode is available 1 The SENSe PERiod NPERiod mode explicitly sets the number of signal periods to measure and average The time it takes the SCP to return a reading is dependent on the input signal period for a given NPERiod setting longer signal periods take longer to return a reading In NPERiod mode the actual m
60. me Type Values Units select discrete string INIT TRIGger seconds ch_list string 100 163 none Comments e In the INIT mode the total is reset only when the INITiate command is executed In the TRIGger mode the total is reset every time a new scan 62 Agilent E1538A Enhanced Frequency Totalize PWM SCP is triggered e If the channels specified are not on a Frequency Totalize SCP an error will be generated Related Commands SENS FUNC TOT INPUT POLARITY RST Condition SENS TOT RESET MODE INIT Send with VXIplug amp play Function hpel14XX_cmd Usage SENS TOT RESET MODE TRIG 134 totalizer at channel 34 resets at each trigger event SENSe TOTalize RESet MODE SENSe TOTalize RESet MODE lt channel gt returns the reset mode for the totalizer channel in lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments Channel must specify a single channel e If the channel specified is not on a frequency totalize SCP an error will be generated Returned Value returns INIT or TRIG The type is string Send with VXIplug amp play Function hpel14XX_cmdString_Q SOURCce FM STATe SOURce FM STATe lt enable gt lt ch_list gt enables the Frequency Modulated mode for a PULSe channel Parameters Parameter Parameter Range of Default Name Type Values Units enable boolean uint16 1101 ON OFF
61. measurement SENS PER MODE must be set to APERture e If the channels specified are on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual for its capabilities Related Commands SENS PER MODE SENS PER NPERiods SENS PER LIM UPPer SENS PER RANGE SENS FUNC PER e RST Condition 001 sec Send with VXIplug amp play Function hpel14XX_cmd Usage SENS PER APER 01 144 set channel 44 aperture to 10msec 56 Agilent E1538A Enhanced Frequency Totalize PWM SCP SENSe PERiod APERture SENSe PERiod APERture lt channefk returns the currently set APERture time Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments e If the channel specified is on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual for its capabilities Related Commands SENS PER APER e Returned Value returns numeric aperture in seconds The type is float32 Send with VXIplug amp play Function hpel4XX_cmdReal64_Q SENSe PERiod LIMit UPPer SENSe PERiod LIMit UPPer lt per_limit gt lt ch_list gt allows you to specify a period upper limit beyond which the E1538A will stop waiting for a signal transition and will return a period value of zero Conceptually this is an input signal period time out Parameters Parameter
62. must be channels on an E1538A SCP This feature is only available when the NPERiods period mode is in use SENSe PERiod MODE NPERiods lt ch_list gt Related Commands SENSe PERiod MODE RESET Condition is MINimum i e 1 Send with VXIplug amp play Function hpel4XX_cmd 60 Agilent E1538A Enhanced Frequency Totalize PWM SCP SENSe PERiod NPERiods SENSe PERiod NPERiods lt channel gt returns the number of signal periods the SCP will measure and average to calculate the signal period Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must be single channel on an E1538A SCP e RETURNS uint32 value which is the current period count configured Related Commands SENSe PERiod NPERiods RST condition SENSe PERiod NPERiods 1 Send with VXIplug amp play Function hpel4XX_cmdInt32_Q SENSe PERiod RANGe UPPer SENSe PERiod RANGe UPPer lt range gt lt ch_list gt can extend the range of period measurement from the default 1 second maximum to a 4 second maximum Parameters Parameter Parameter Range of Default Name Type Values Units range numeric float32 1141MAXimum MINimum Sec ch_list string 100 163 none Comments e lt ch_list gt must be channels on an E1538A SCP Range 1 0 sec provides period measurement in the range 10usec
63. nal periods NPERiods Parameters Parameter Parameter Range of Default Name Type Values Units mode discrete string APERture NPERiods none ch_list string 100 163 none Comments The SENS PER APERture command sets the aperture value The SENS PER NPERiods command sets the nperiods value e lt ch_list gt must be channels on E1538A SCPs Related Commands SENS PER APERture SENS PER NPERiods SENS FUNC PER SENS PER LIM UPPer RST Condition is APERture Send with VXIplug amp play Function hpel4XX_cmd Agilent E1538A Enhanced Frequency Totalize PWM SCP 59 SENSe PERiod MODE SENSe PERiod MODE lt channeb returns the measurement interval mode currently set for period measurement Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must be a single channel on an E1538A SCP e RETURNS String value APER or NPER Type is String Send with VXIplug amp play Function hpel4XX_cmdString Q SENSe PERiod NPERiods SENSe PERiod NPERiods lt count gt lt ch_list gt sets the number of signal periods to measure and average in order to compute the input signal period Parameters Parameter Parameter Range of Default Name Type Values Units count numeric uint32 1 to 255 MINimum MAXimum seconds ch_list string 100 163 none Comments e lt ch_list gt
64. ncy LIMit _OWer SENSe FREQuency LIMit LOWer lt freq_limit gt lt ch_list gt allows you to specify a frequency lower limit beyond which the E1538A will stop waiting for a signal transition and will return a frequency value of zero Conceptually this is an input signal period time out Parameters Parameter Parameter Range of Default Name Type Values Units freq_limit numeric float32 01667 to 250 Hz ch_list string 100 163 none Comments lt ch_list gt must be channels on an E1538A SCP Note Although SENS FREQ LIM LOW can set a timeout period as long as 60 seconds 01667Hz the lowest frequency measurement supported by the E1538A is 1 Hertz The period associated with the FREQ LIMit LOWer frequency is the time the SCP will allow for any single cycle period At any time during the frequency measurement if the signal s period 48 Agilent E1538A Enhanced Frequency Totalize PWM SCP Note 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
65. ne quadrature pair and channels 48 and 49 as another pair RST SENS FUNC QUAD 8192 142 143 pair 42 amp 43 preset to count of 8192 SENS FUNC QUAD 0 148 149 pair 48 amp 49 preset to 0 algorithm will retrieve values from input channels and place in CVT elements ALG DEF ALG1 writecvt I1142 42 writecvt l148 48 INIT start algorithm execution begin loop loops between here and end loop SENS DATA CVT 42 48 get quadrature position count display or otherwise use count info end loop Agilent E1538A Enhanced Frequency Totalize PWM SCP 21 Inputs read at beginning of each algorithm execution T INITiate here i Rotation Signal at High Channel Ine re a 2 WO leads B i clockwise Count as read by algorithm 4096 l l l l l l l counter clockwise Ay Clockwise Pulse Generator Clockwise i Rotation Signal at High Channel PYF WE LAA LE B leads A Count as read by algorithm 4120 Sense Rotational Velocity Signal at Low Channel eee Te Te li m j Counter I l l l l l l l 4102 4108 4114 4120 Rotary l l l l l ji l Figure 13 Sense Quadrature Position This means that the E1538 will read the rotational velocity of a toothed wheel sensor The E1538 measures tooth to tooth period
66. ng Output Use OUTPut POLarity NORMal INVerted lt ch_list gt to configure Polarity output channel logic sense The operations is as follows OUTP POL NORM a logical 1 output from the algorithm or generated within the E1538 single or repetitive pulses will turn off the output transistor can be pulled up OUT POL INV a logical 1 output from the algorithm or generated within the E1538 single or repetitive pulses will turn off the output transistor pulls low To configure channels 40 to 43 to drive their outputs low for a logic 1 OUTP POL INV 140 143 Output Static This means setting a channel s digital state when an algorithm executes To Digital State set individual channels to this function use the SCPI command SOURce FUNCtion SHAPe CONDition lt ch_list gt To configure channels 40 through 43 as static digital outputs send RST SOUR FUNC COND 140 148 default for all digital outputs ALG DEF ALG1 static float chO 0 ch1 1 ch2 0 ch3 1 O140 ch0 0141 ch1 0142 ch2 0143 ch3 INIT Output occurrs only at the end of each algorithm execution Es a i D in iga is Algorithm Executions Output Data in Algorithm 0 1 1 0 0 for example 0132 1 Signal from Output Channel Figure 15 Output Static Levels 24 Agilent E1538A Enhanced Frequency Totalize PWM SCP Variable Width Pulse Per Trigger Output occurrs only at the end of each algorithm ex
67. none ch_list string 100 163 none Comments This command is coupled with the SOURce PULM STATE command If the FM state is ON then the PULM state is OFF If the PULM state Agilent E1538A Enhanced Frequency Totalize PWM SCP 63 is ON then the FM state is OFF If both the FM and the PULM states are OFF then the PULSe channel is in the single pulse mode e If the channels specified are not on a Frequency Totalize SCP an error will be generated Use SOURce FUNCtion SHAPe SQUare to set FM pulse train to 50 duty cycle Use SOURce PULSe PERiod to set the period RST Condition SOUR FM STATE OFF SOUR PULM STATE OFF SENS FUNC COND and INP POL for all digital SCP channels Related Commands SOUR PULM STATe SOUR PULS POLarity SOUR PULS PERiod SOUR FUNC SHAPe SQUare Send with VXIplug amp play Function hpel4XX_cmd Usage The variable frequency control for this channel is provided by the algorithm lan guage When the algorithm executes an assignment statement to this channel the value assigned will be the frequency setting For example O1 SOURce FM STATe 43 2000 set channel 43 to 2KHz SOURce FM STATe lt channel gt returns the frequency modulated mode state for a PULSe channel Parameters Parameter Name channel Parameter Range of Default Type Values Units string 100 163 none Comments Channel must specify a sing
68. nts lt channel gt must specify a single channel only Usage SOUR RPULSE POS ANGL 1 45 return pulse pos set for channel 45 SOUR RPULse VARType SOUR RPULse VARType lt itype gt lt ch_list gt specifies the type of value that will be controlled varied by the algorithm Depending on how the RPULse system is set up the varied property can be either pulse position or pulse width Parameters Parameter Parameter Range of Default Name Type Values Units type discrete string TIME ANGLe seconds ch_list string 100 163 none Comments e lt type gt specifies the that the algorithm will send values of either ANGLe in degrees to the channel s or TIME in seconds to the channel s lt ch_list gt specifies the SOUR FUNC RPUL channel s that will be controlled varied by the algorithm Channels in lt ch_list gt must be referenced in a SOUR FUNC RPUL command before the next INIT command Related error messages 3113 Channel specified is not in same SCP as reference channel 3114 First channel in SCP can not be used in RPULse output channel list Usage SOUR RPULSE VART ANGL 145 147 algorithm will control pulse width by ANGLE Agilent E1538A Enhanced Frequency Totalize PWM SCP 73 SOUR RPULSE VART TIME 1 43 1 44 algorithm will control pulse width by TIME SOUR RPULse VARType SOUR RPULse VARType lt channel gt returns the type of value that will be controlled v
69. ompatible with variable reluctance sensors For a discussion on using the VRS mode see VRS Mode Input Operation on page 10 Locating switches Figure 2 shows the location of each channel s configuration switches Board Viewed With Variable Reluctance Connectors Behind Sensor Enable Channels 1 0 Use VRS adaptive input amplifiers only available on Pull up Enable channels 0 amp 1 Channels NOfWN O Enable channels 2 amp 3 as outputs Channels white square is switch handle NOuRWN AO Figure 2 Switch Location and Example Settings Configuring Input Refer to Figure 2 for the location of the eight Output Enable OE switches Output direction Move the channel s switch handle to the ON position for output and to the OFF position for input Configuring Channel Refer to Figure 2 for the location of the eight Pull up Enable PU switches Pull up Resistor Move the switch handle to the ON position to connect the pull up resistor connected from channel terminal to an internal 5V and to the OFF position to disconnect the pull up resistor high impedance input open drain output Note Pull Up enable ON is not allowed for channels that have their VRS enable ON VRS is only available on channels 0 and 1 6 Agilent E1538A Enhanced Frequency Totalize PWM SCP Installation Installation for this Plug on is identical to other SCPs and is covered in Chapter 1 of your
70. on page 23 even though with the missing tooth there are only 11 lt index_type gt can be either of the strings MISSing or EXTRa lt ch_list gt must be the first channel on the SCP but can contain more than one channel provided that each channel is on a separate E1538 See following note The related Error Messages are 3110 Channel specified is invalid for RVELocity function Note Only one channel on any E1538 SCP can be assigned to the SENS FUNC RVEL function and it must be the first channel on the SCP RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpel14XX_cmd Usage See Sense Rotational Velocity on page 22 SENSE FUNC RVEL 12 MISSING 140 12 toothed wheel with one missing from channel 40 54 Agilent E1538A Enhanced Frequency Totalize PWM SCP SENSe FUNCtion TOTalize SENSe FUNCtion TOTalize lt ch_list gt sets the SENSe function to TOTalize for channels in lt ch_list gt See Totalize Positive or Negative Edge State Changes on page 15 Parameters Parameter Parameter Range of Default Name Type Values Units ch_list string 100 163 none Comments The totalize function counts rising edges of digital transitions at Frequency Totalize SCP channels The counter is 24 bits wide and can count up to 16 777 215 The SENS TOT RESET MODE command controls which events will reset the c
71. ounter e If the channels specified are not on a Frequency Totalize SCP an error will be generated Related Commands SENS TOT RESET MODE INPUT POLARITY RST Condition SENS FUNC COND and INP POL NORM for all digital SCP channels Send with VXIplug amp play Function hpel4XX_cmd Usage See Totalize Positive or Negative Edge State Changes on page 15 SENS FUNC TOT 134 channel 34 is a totalizer Agilent E1538A Enhanced Frequency Totalize PWM SCP 55 SENSe PERiod APERture SENSe PERiod APERture lt aperture gt lt ch_list gt sets the time allowed to determine signal period and return a reading to the algorithm When AP ERture is large enough to contain more than one signal period the SCP measures and averages the number of signal periods that will fit within this APERture time If the specified APERture is less than the input signal period the SCP stretches the aperture in order to measure at least one signal period This is known a Adaptive Aperture Parameters Parameter Parameter Range of Default Name Type Values Units aperture numeric float32 see text seconds ch_list string 100 163 none Comments The range for lt aperture gt is dependent on SENS PER RANGE When SENS PER RANGE is 1 lt aperture gt can range from 001 to 1 second When SENS PER RANGE is 4 lt aperture gt can range froom 004 to 4 seconds For APERture to effect the
72. quency Totalize PWM SCP 9 is to maintain a constant level digital output while the input varies from millivolts to several tens of volts For simple sensing of switches and open collector logic devices a channel s pull up resistor can be connected by closing its PU switch g o Wee erred eee channels 0 and 1 only lt lt gt 2g 2 D 1K Adaptive aS 10K Zero Cross H gt VRS Input Data amp 5 F Detector aaa 2s Hi z PU EnS E A E A A ea ET pull up enable Threshold Comparator gt Normal Input Data 12V i OE output enable Threshold DAC lt __ Threshold Control Output Data Figure 6 The E1538A Input Output Characteristics VRS Mode __ When the VRS configuration switch is set to on the input signal conditioning Input Operation SCP for that channel is changed to make it compatible with a typical variable channels 0 amp 1 only reluctance sensor The variable reluctance sensor is commonly used to detect rotational shaft position and or velocity Because the voltage output of a VRS is proportional to the rate of change of a magnetic field different rotational velocities generate different signal amplitudes The VRS configured channel detects the negative going zero crossing point of the signal To minimize the effects of input noise the zero crossing detector can only be triggered if the positive going portion of the signal exceeded an arming threshold The arming ci
73. rcuit is reset when zero crossing detector is triggered so it cant re trigger until after the signal exceeds the arming threshold again The arming threshold tracks the positive peak input level and is 80 of this peak value By sensing the zero crossing point of the input signal the VRS mode isolates signal amplitude changes from affecting signal timing Note VRS enable ON is not allowed if PU enable is ON At high rotational speeds variable reluctance sensors can generate voltage levels over 100V AC The VRS inputs must be protected against signal levels over 17 5 Volts If your VRS will generate voltages over 17 5 you must provide a resistor in series with the VRS input The user supplied resistor together with the VRS input s 5 38K input impedance form a voltage divider that attenuates the input signal at the channel s Hi input terminal Use the 10 Agilent E1538A Enhanced Frequency Totalize PWM SCP sensor 17 5 Se 0 0032 to calculate the protection resistor s value Figure 7 shows the VRS mode input characteristics formula R arm level tracks at ri 80 of peak signal Input signal from sensor TN S N J N J N internal signal from VRS Variable ing detector Reluctance zero crossing uean input to SCP function Figure 7 VRS Mode Input Characteristics Output Characteristics The output stage of the E1538A is simply a MOS FET transistor that is configured as open drain when the pull up resistor i
74. rithm running later adjust channel 46 s position while algorithm running later adjust channel 47 s position while algorithm running values in update queue sent to variables pulse width fixed by time _ before INITiate command Figure 22 Variable Position Width Preset by Time Rotational Pulse Mode Variable Pulse Width by angle Preset Angular Position In this mode the angular pulse width is controlled by the algorithm and the angular position is preset before INIT See Figure 23 Use the following command sequence SOURce FUNCtion RPULse lt ref_channel gt lt ch_list gt to select the channels that will output angular positioned pulses and to specify the reference channel Agilent E1538A Enhanced Frequency Totalize PWM SCP 33 SOURce RPULse POSition ANGLe lt degrees gt lt ch_list gt to preset the angular pulse position in degrees The algorithm will control the pulse duration SOUR RPULse VARType ANGLe lt ch_list gt to set the type of value that will vary with algorithm control in this case pulse width ANGLe Example of variable width by angle preset position Set up channel 40 as the reference channel and channels 45 through 47 to output variable width pulses RST SENS FUNC RVEL 12 MISS 140 sense rvel for reference channel SOUR FUNC RPULSE 140 145 147 3 rotational pulse output chans SOUR RPULSE POS ANGL 20 145 preset channel 45 pulse position to 20 degrees SOU
75. rogramming information Agilent VEE User s Manual Supplied with Agilent Command Modules Embedded Controllers and VXLink Manual Part Number E1538 90004 Printed in U S A E0600 Agilent E1538A Enhanced Frequency Totalize PWM SCP About this Manual This manual describes how to configure the Signal Conditioning Plug on SCP using SCPI commands and explains the capabilities of this SCP The contents of this manual are Introductions snien iiaa deh Mab bad ale hogs hee page 4 Identifying the Plug on IMPORTANT page 5 Setting Configuration Switches page 6 Installation 5 2 2 e ph n sna nad Magee eae es page 7 Connecting To The Terminal Module page 7 Recommended Signal Connections page 8 Input and Output Characteristics 04 page 9 Programming With SCPI Commands page 11 Configuring I O Direction page 12 Programming Input Channels page 12 Setting the Input Threshold Level page 12 Set Input Logic Sense 0 0 0 0 0000000 page 13 Reading Static Digital State 0 page 14 Totalize Positive or Negative Edge State Changes page 15 About Period and Frequency Measurements page 16 Measure Frequency E ee eee eee eee page 17 Measure Period is nr oti ne wi Autre taints page 18 M
76. s considered a logic one Note The value sent for lt evel gt will be rounded to the nearest multiple of 0 375 Volts For instance 5 would be 4 875 10 would be 10 125 9 5 would be 9 375 and 15 would be 15 The INP THR LEV query will return the actual setting Related Commands INPut POLarity INP THR LEV e RST Condition INP THR LEV 1 875 Send with VXIplug amp play Function hpel4XX_cmd INPut THReshold LEVel INPut THReshold LEVel lt channeb returns the threshold level set for lt channel gt Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments lt channel gt must specify a single channel Agilent E1538A Enhanced Frequency Totalize PWM SCP 45 Note Because the E1538 rounds lt evel gt to the nearest multiple of 0 375 the returned value can be different from the value sent INP THR LEV returns a numeric value between 46 and 46 The C SCPI type is float32 Related Commands NPut POLarity INP THR LEVel e RST Condition INP THR LEV 1 875 e Send with VXIplug amp play Function hpel14XX_cmdReal64_Q Usage To query the threshold level on the second channel at SCP position 4 send INP THR LEV 133 query 2nd chan on SCP pos 4 enter statement here OUTPut POLarity OUTPut POLarity lt select gt lt ch_list gt sets the polarity on digital
77. s not connected PU switch is OFF For simple interfacing to logic devices the pull up resistor can be connected by turning the PU switch ON Operating voltages output transistor off at an output configured channel can range from 0 to 48 volts The output can sink up to 100mA of current output transistor on Caution If the Hnn terminal is driven below the Lnn terminal while a channel is output configured an inherent diode in the output transistor will conduct heavily This reverse current must be limited to 100mA or damage to the SCP could result Note The RST and power on condition true also after TST for output configured channels will output a logical one open drain output off You should keep this behavior in mind when applying the E1415 to your system It is best to have your system s digital inputs use a high one as their safe state Programming With SCPI Commands The SCPI commands shown here configure E1538 functions The E1415 and E1419 dont provide SCPI commands to read an input channel or control an output channel This communication with the SCP is provided by the Algorithm Language Examples will show communication with algorithms Agilent E1538A Enhanced Frequency Totalize PWM SCP 11 Checking the ID of the SCP Configuring the Channels Configuring I O Direction Programming Input Channels Setting the Input Threshold Level Note To verify the SCP type s installed on your VXI mo
78. t ch_list gt to configure the frequency counter channels measurement interval Use SENSe FUNCtion FREQuency lt ch_list gt to configure channels to measure signal frequency To measure frequency at channel 45 with aperture of 1 second RST TRIGGER TIMER 2 SENS FUNC FREQ 145 SENS FREQ APER 1 145 ALG DEF ALG1 writecvt 1145 45 INIT do loop SENS DATA CVT 45 read value from CVT query above end loop Alg executes at 2 sec intervals ch 45 is frequency counter meas and avg sig periods for 1S alg puts frequency in CVT start algorithm execution get frequency from CVT algorithm execution INITiate here Algorithm Executions set by TRIG TIMER Signal at Input Channel 1KHz Freq Value Read by Algorithm 998 Average signal periods for APERture time 7 i 998 f 998 998 998 1000 1000 All values returned before average is complete sie a are from a single period measurement a Pa a SCP averages signal periods in this example for one second then converts to frequency Figure 10 Input Frequency Agilent E1538A Enhanced Frequency Totalize PWM SCP 17 Measure Period Use SENSe PERiod MODe APERture NPERiods lt ch_list gt to select the measurement interval setting mode Depending on the mode selected above use SENSe PERiod APERture lt time gt lt ch_list gt or use SENSe PERiod NPERiods lt n_periods gt lt ch_list gt to s
79. th by time Preset Angular Position In this mode the pulse duration in seconds is controlled by the algorithm and the angular position is preset before INIT See Figure 24 Use the following command sequence SOURce FUNCtion RPULse lt ref_channel gt lt ch_list gt to select the channels that will output angular positioned pulses and to specify the reference channel SOURce RPULse POSition ANGLe lt degrees gt lt ch_list gt to preset the angular pulse position in degrees The algorithm will control the pulse duration SOUR RPULse VARType TIME lt ch_list gt to set the type of value that will vary with algorithm control in this case pulse duration in seconds Example of variable width by time preset position Set up channel 40 as the reference channel and channels 45 through 47 to output variable width pulses RST SENS FUNC RVEL 12 MISS 140 sense rvel for reference channel SOUR FUNC RPULSE 140 145 147 3 rotational pulse output chans SOUR RPULSE POS ANGL 20 145 preset channel 45 pulse position to 20 degrees Agilent E1538A Enhanced Frequency Totalize PWM SCP 35 algorithm controlled pulse width by time SOUR RPULSE POS ANGL 140 146 SOUR RPULSE POS ANGL 260 147 SOUR RPULSE VART TIME 145 147 preset channel 46 pulse position to 140 degrees preset channel 47 pulse position to 260 degrees algorithm will control pulse duration by TIME Algorithm outputs pulses on al
80. th gt lt index_type gt lt ch_list gt configures the first channel on E1538s to measure the rotational velocity of a toothed wheel sensor The E1538 measures tooth to tooth period and converts it into units of revolutions per second RPS See Sense Rotational Velocity on page 22 Agilent E1538A Enhanced Frequency Totalize PWM SCP 53 Parameters Parameter Parameter Range of Default Name Type Values Units N_teeth numeric int32 3 to 255 none index_type string MISSing EXTRa none ch_list string 100 163 none Comments This function can only be linked to the E1538 s first channel The function works for wheels that have either a missing or an extra tooth to mark their index position Figure 14 on page 23 shows a wheel sensed with a variable reluctance sensor using the VRS input option but any wheel sensing method is applicable as long as it provides a digital output to the RVEL channel RPS to 100 000 nteeth nteeth The value read by the algorithm can range from RPS e As well as sensing rotational velocity SENS FUNC RVEL provides the reference position to the SOUR FUNC RPULse function that generates angular positioned pulses See page 30 for more information on RPULse lt n_teeth gt is the number of teeth that the wheel would have if it didn t have missing or extra teeth For example we would set lt n_teeth gt to 12 for the wheel shown in Figure 14
81. time in seconds to the channel s lt ch_list gt specifies the SOUR FUNC RPUL channel s that will be controlled varied by the algorithm 30 Agilent E1538A Enhanced Frequency Totalize PWM SCP Rotational Pulse Mode Variable Angular Position Preset Pulse Width by angle In this mode the angular position of the pulses is controlled by the algorithm and the width duration in degrees is preset before INIT See Figure 21 Use the following command sequence SOURce FUNCtion RPULse lt ref_channel gt lt ch_list gt to select the channels that will output angular positioned pulses and to specify the reference channel SOURCe RPULse WIDTh ANGLe lt degrees gt lt ch_list gt to preset the pulse width in degrees The algorithm will control the angular pulse position Example of variable position preset width by angle Set up channel 40 as the reference channel and channels 45 through 47 to output variable position pulses RST SENS FUNC RVEL 12 MISS 140 sense rvel for reference channel SOUR FUNC RPULSE 140 145 147 3 rotational pulse output chans SOUR RPULSE WIDT ANGL 15 145 147 preset pulse width to 15 degrees Algorithm outputs pulses on all three channels with variable position ALG DEF ALG1 static float Pos1 Pos2 Pos3 0145 Pos1 0146 Pos2 0147 Pos3 ALG SCALAR ALG1 Pos1 60 ALG SCALAR ALG1 Pos2 180 ALG SCALAR ALG1 Pos3 300 A
82. tput configurable as Open Drain or passive pull up Static digital state Single pulse per trigger Generates a pulse at each algorithm execution The pulse width is controlled by the algorithm Pulse Width Modulation A free running pulse train where a SCPI command pre configures the frequency and the algorithm controls the pulse width Frequency Modulation A free running pulse train where a SCPI command pre configures the pulse width and the algorithm controls the frequency In this FM mode the duty cycle varies with frequency Frequency Modulation A free running pulse train where the duty cycle remains constant at 50 while the algorithm controls the frequency Rotationally positioned pulse The algorithm controls the angular pulse position relative to an input sensing rotational velocity The pulse width is fixed by a SCPI command requires a reference channel in addition to any rotational pulse output channels Rotationally positioned pulse The algorithm controls the width of the pulse The angular pulse position relative to an input sensing rotational velocity is fixed by a SCPI command requires a reference channel Stepper Motor Control Controls 2 phase and 4 phase motors in 4 Agilent E1538A Enhanced Frequency Totalize PWM SCP both full and half step modes requires 2 or 4 channels The logical sense of input and output channels can be configured as inverted or normal Input configure
83. ts Send with VXIplug amp play Function hpe14XX_cmd Usage The frequency control for these channels is provided by the algorithm language function 0143 2000 set channel 43 to 2KHz SOURce FUNCtion STEPper SOURce FUNCtion STEPper lt preset_pos gt lt mode gt lt max_vel gt lt min _vel gt lt ch_list gt controls 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 See Stepper Motor Control on page 37 Parameters Parameter Parameter Range of Default Name Type Values Units preset_pos discrete string see text none mode see text none max_vel none min_vel none ch_list string 100 163 none Comments e lt preset_pos gt defines the position count at algorithm start up This is an unsigned 16 bit integer and can range from 0 to 65 535 for full speed modes SF or 0 to 32 767 for half speed modes SH Agilent E1538A Enhanced Frequency Totalize PWM SCP 67 e lt mode gt is used to select the stepping mode the allowable values are Table 3 Stepping lt mode gt values lt mode gt 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
84. ture in order to measure at least one signal period This is known a Adaptive Aperture Parameters Parameter Parameter Range of Default Name Type Values Units aperture numeric float32 001 to 1 001 resolution seconds ch_list string 100 163 none Comments For APERture to effect the measurement SENS FREQ MODE must be set to APERture e If the channels specified are on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual for its capabilities Related Commands SENS FREQ MODE SENS FREQ NPERiods SENS FREQ LIM LOWer SENS FUNC FREQ e RST Condition 001 sec Send with VXIplug amp play Function hpel14XX_cmd Usage SENS FREQ APER 01 144 set channel 44 aperture to 10msec Agilent E1538A Enhanced Frequency Totalize PWM SCP 47 SENSe FREQuency APERture SENSe FREQuency APERture lt channef returns the currently set APERture time Parameters Parameter Parameter Range of Default Name Type Values Units channel string 100 163 none Comments e If the channel specified is on an SCP that doesn t support this function an error will be generated See your SCP s User s Manual for its capabilities Related Commands SENS FREQ APER Returned Value returns numeric aperture in seconds The type is float32 Send with VXIplug amp play Function hpel4XX_cmdReal64_Q SENSe FREQue
85. uency Totalize PWM SCP heavy line indicates side of l terminal block wire enters Figure 4 E1419A Option 11 Terminal Module Connections Recommended Signal Connections Figure 5 shows the recommended method of wiring digital I O channels as well as the maximum voltage limitations for the E1538A Figure 5 shows the shields connected directly to the E1415 ground This is to limit potential noise on the digital wiring from affecting low level analog channel wiring within the Terminal Module Note The G analog guard terminals are connected through 10K Ohm resistors to chassis ground To connect the shields directly to chassis ground on the E1415 and the E1419 Option 12 Terminal Module install the guard to ground jumpers for the E1538 channels 8 Agilent E1538A Enhanced Frequency Totalize PWM SCP Input Configured HP E1538 Channel Intput configured channel Dig Gnd OV shielded twisted pair E1415 19 s analog ground common to all channels For input configured channels Hnn use guard to _ can be driven above or below Lnn ground jumper i Gnn HP E1415 19 s Chassis Ground terminal b
86. ur system It is best to have your system s digital inputs use a high one as their safe state Agilent E1538A Enhanced Frequency Totalize PWM SCP 41 SCPI Command Reference Most of the E1538 s commands were available since its introduction A small number of commands are only available with E1538 s built after February 1998 The following table indicates these new commands with an X in the for newer units only column See Identifying the Plug on on page 5 Table 2 Command Syntax For newer Page units only Discussed INPut POLarity NORM INV lt ch_list gt 44 INPut POLarity lt ch_list gt 44 INPut THReshold LEVel lt devel gt lt ch_list gt 45 INPut THReshold LEVel lt channel gt 45 SENSe FUNCtion CONDition lt ch_list gt 50 SENSe FUNCtion FREQuency lt ch_list gt 51 SENSe FREQuency APERture lt time gt lt ch_list gt 47 SENSe FREQuency APERture lt channel gt 48 SENSe FREQuency LIMit LOWer lt freq_limit gt lt ch_list gt X 48 SENSe FREQuency LIMit LOWer lt channel gt X 50 SENSe FUNCtion PERiod lt ch_list gt X 51 SENSe PERiod APERture lt time gt lt ch_list gt X 56 SENSe PERiod APERture lt channel gt X a7 SENSe PERiod LIMit UPPer lt per_limit gt lt ch_list gt X EFi SENSe PERiod LIMit UPPer lt channel gt X 59 SENSe PERiod MODE APERture NPERiods lt ch_list gt X 59 SENSe PERiod MODE lt channel gt X 60 SENSe PERiod NPERio
87. ure 16 Output Variable Width Pulse per Trigger Agilent E1538A Enhanced Frequency Totalize PWM SCP 25 Variable Width Pulse This means that the E1538 outputs a continuous train of pulses whose logic Train PWM pulse width is controlled by the algorithm The frequency is set by a SCPI command before INIT Use the following command sequence to set up this mode SOURce FUNCtion PULSe lt ch_list gt to enable pulse generation SOURce PULM STATe ON lt ch_list gt to select the PWM mode SOURce PULSe PERiod lt period gt lt ch_list gt to set the pulse repetition period frequency 1 lt period gt lt period gt can range from 25uSec to 7 812mSec The pulse width value sent by the algorithm can range from 7 87 uSec to lt period gt 7 87uSec Resolution within this range is 238 4nSec 100 duty cycle is output when the algorithm sends a value greater than or equal to lt period gt 0 duty cycle is output when the algorithm sends a value less than or equal to 0 To configure channel 45 to output a variable pulse width continuous train SOUR FUNC PULS 145 channel sources pulses SOUR PULM ON 145 and continuous PWM train SOUR PULS PER 0005 145 5 msec period 2KHz freq The algorithm can now output a value to channel 45 to control pulse width of the logic 1 portion of the waveform 0145 333E 6 channel 45 pulse width will be 333 usec Output changes only at the end of each algorithm execution x Iy a X

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