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NI PXI-4224 User Manual

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1. esee 10 ns min Impedance nenne niter 10 kQ COUPLING ido n DC Tngger ines aee deed 6 Star CLE BOL iuste tote 1 Master slave Power Requirements Physical NI PXI 4224 User Manual 2 A at 5 VDC 2590 13 0 cm 5 12 in BTE aia a 21 3 cm 8 39 in Figure A 1 PXI 4224 Dimensions A 4 ni com Appendix A Specifications for Weight te tete edet 279 g 9 8 oz Analog input signal connector 25 Pin D SUB Maximum Working Voltage Signal common mode each input should remain within 42 4 V peak or 60 VDC of ground Maximum working voltage refers to the signal voltage plus the CMV Channel to earth inputs 42 4 V peak or 60 VDC Measurement Category I Channel to channel inputs 42 4 V peak or 60 VDC Measurement Category I N Caution This device is rated for Measurement Category I and is intended to carry signal voltages no greater than 42 4V peak or 60 VDC Do not use this device for connection to signals or for measurements within Categories II II or IV Isolation Voltages Channel to channel channel to earth isolation Conpnuoug sssssseeerererereesesesrrerrrree 60 VDC Measurement Category I Withstand sien 850 Vms verified by a5 s dielectric withstand type test Channel to bus Continuous ssssennnseseoseeeesseessseeeeee 60 VDC Measur
2. 1 ACCESS and ACTIVE LEDs 3 25 Pin D SUB or TB 2725 Terminal 2 SMB PFI 0 CAL Connector Block Connector Figure 2 1 NI PXI 4224 Front Label Analog Input Connections The following sections provide a definition of the signal source characteristics descriptions of various ways to connect signals to the NI PXI 4224 and electrical diagrams showing the signal source and connections Whenever possible use shielded twisted pair field wiring and grounding to reduce the effects of unwanted noise sources National Instruments Corporation 2 3 NI PXI 4224 User Manual Chapter 2 Connecting Signals In the electrical diagrams two different ground symbols are used These symbols indicate that you cannot assume that the indicated grounds are at the same potential Refer to Appendix A Specifications for maximum working voltage specifications You can make signal connections to the NI PXI 4224 through either an NI terminal block such as the TB 2725 or you can build a connector using a 25 pin D SUB Caution If you are building a 25 pin D SUB connector for your application make sure you use a connector and signal wires that are safety rated for the voltage and category of the signals in your application Figures 2 2 through 2 5 illustrate connecting signals using a D SUB connector Signal Source Vai Twisted Pair CH 0 Wiring AlO AIO e cH Al 7 AI7 S
3. NI PXI 4224 User Manual Figure 2 6 Unshielded Floating Signal Source Connection Using a Terminal Block 2 8 ni com Chapter 2 Connecting Signals Signal Source Vai Voig Ground Reference Twisted Pair Wiring Terminal Block CHO E e e e Figure 2 7 Unshielded Grounded Signal Source Connection Using a Terminal Block National Instruments Corporation 2 9 NI PXI 4224 User Manual Chapter 2 Connecting Signals Signal Source Twisted Pair Wiring Shielding Terminal Block AIO AIO AL7 AI 7 CHO e e cH WD Fr NI PXI 4224 User Manual Figure 2 8 Shielded Floating Signal Source Connection Using a Terminal Block 2 10 ni com Chapter 2 Connecting Signals Twisted Pair m Signal Source Wiring Shielding Terminal Block E md AIO an p g Vsig ES i o AIO e a we Veg Ground e Reference CH7 KEE 7 ALT SH AI 7 9 mm CH National Instruments Corporation Figure 2 9 Shielded Grounded Signal Source Connection Using a Terminal Block Floating Signal Source Connection Figures 2 2 2 4 2 6 and 2 8 illustrate floating signal source connections In this configuration the signal source being measured is a floating signal source such as a b
4. Figure 4 2 Effect of Input Impedance on Signal Measurements Although Rs does not influence DC measurements take care when measuring AC signals since Co attenuates higher frequencies if Rs is too large For example V VsigRin MEAS Rs Rigs 1 Bandwidth J C Common Mode Rejection Ratio The ability of a measurement device to reject voltages that are common to both input terminals is referred to as the common mode rejection ratio CMRR The CMMR is usually stated in decibels at a given frequency or over a given frequency band of interest Common mode signals can arise from a variety of sources and can be induced through conductive or radiated means One of the most common sources of common mode interference is 50 or 60 Hz powerline noise The minimum NI PXI 4224 CMRR is 140 dB which results in a reduction of CMV by a factor of 10 000 000 NI PXI 4224 User Manual 4 4 ni com Chapter 4 Theory of Operation Effective CMR When the frequency of a common mode signal is known and outside of the measurement frequency band of interest you can use an analog or digital filter or both to further reduce the residual error left from the finite CMRR of the instrument The combined CMR of the instrument and the filter attenuation results in an effective CMR When expressed in decibels the effective CMR is equal to the sum of the CMRR and the attenuation due to the filter at a specified frequency Timing and Contro
5. Positive of or plus Negative of or minus Q Ohm A A Amperes A D Analog to digital AC Alternating current National Instruments Corporation G 1 NI PXI 4224 User Manual Glossary ADC ADE AI AI CONV CLK AI HOLD COMPLETE AI PAUSE TRIG AI SAMP CLK bandwidth bipolar breakdown voltage bus CalDAC CH channel clock NI PXI 4224 User Manual Analog to digital converter An electronic device often an integrated circuit that converts an analog voltage to a digital number Application development environment Analog input Convert signal Scan clock signal Analog input gate signal Start scan signal The range of frequencies present in a signal or the range of frequencies to which a measuring device can respond A signal range that includes both positive and negative values for example 5 to 5 V The voltage high enough to cause breakdown of optical isolation semiconductors or dielectric materials See also working voltage The group of conductors that interconnect individual circuitry in a computer Typically a bus is the expansion vehicle to which I O or other devices are connected An example of a PC bus is the PCI bus Celsius Calibration DAC Channel Pin or wire lead to which you apply or from which you read the analog or digital signal Analog signals can be single ended or differential For digital signals you group channels to form ports Ports usu
6. to the channel reference AI X This shielding scheme is effective at reducing capacitive or electrically coupled noise The same concerns regarding the difference in ground potentials discussed in the Ground Referenced Signal Connection section also apply to this configuration For more information about the function of the NI PXI 4224 and other measurement considerations refer to Chapter 4 Theory of Operation 2 12 ni com Configuring and Testing This chapter provides details about configuring and testing the NI PXI 4224 in MAX including how to use device test panels and create and configure NI DAQmx Tasks and NI DAQmx Global Channels Verifying and Self Testing the Signals Using Test Panels After you have successfully installed the NI PXI 4224 verified the installation and connected the signals use the NI PXI 4224 device test panels to verify the device is measuring signals properly The test panels allow you to measure the signal connected to the NI PXI 4224 directly as well as configure some of the properties of your measurement To open the NI PXI 4224 device test panels when in MAX complete the following steps 1 Expand Devices and Interfaces to display the list of devices and interfaces Expand NI DAQmx Devices to display the list of NI DAQmx devices Click PXI 4224 Click the Test Panels button in the device toolbar pedes passu Configure the settings on the screen and click Start to take a
7. Search Drivers and Updates 3 Enter the keyword NI DAQ to find the latest version of NI DAQ for your operating system Does the NI PXI 4224 have hardware analog triggering No Is the NI PXI 4224 an isolated device Yes the NI PXI 4224 provides true channel to channel and channel to chassis isolation When no signal is connected to the NI PXI 4224 what behavior should I expect While the NI PXI 4224 may react differently because of system and condition variables in most cases a channel drifts to one extreme output To prevent this behavior short the inputs to unused channels How do I program the NI PXI 4224 Refer to Chapter 4 Theory of Operation or your ADE help file for application programming information There is no register level programming manual available for the NI PXI 4224 National Instruments Corporation D 1 NI PXI 4224 User Manual Appendix D Common Questions How do I perform an external calibration of the NI PXI 4224 As of the NI PXI 4224 release an external calibration document is not available To check the availability of an NI PXI 4224 external calibration document is go to ni com calibration and click Manual Calibration Procedures NI PXI 4224 User Manual D 2 ni com Glossary Symbol Prefix Value p pico 10 2 n nano 107 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 T tera 102 Symbols Per Degree Percent
8. YY Figure 4 4 NI PXI 4224 PXI Trigger Bus Signal Connection NI PXI 4224 User Manual 4 8 ni com Chapter 4 Theory of Operation Table 4 2 provides more information about each of the timing signals available on the PXI trigger bus For more detailed timing signal information refer to Appendix B Timing Signal Information Table 4 2 PXI Trigger Bus Timing Signals Availability Availability on PFI 0 on PXI Signal Direction Description SMB Trigger Bus AI START TRIG Input This trigger is the source for the Input Input analog input digital start trigger which is the trigger that begins an acquisition Output This trigger sends out the actual Output Output analog input start trigger AI PAUSE TRIG Input This signal can pause and resume Input Input acquisition AI SAMPLE CLK Input This timebase provides the master Input Input TIMEBASE clock from which the sample clocks are derived AI HOLD Output This signal is output when the Not Not COMPLETE analog signal to be converted by available available the ADC has been held National Instruments Corporation 4 9 NI PXI 4224 User Manual Using the NI PXI 4224 This chapter describes how to program the NI PXI 4224 using DAQ Assistant or LabVIEW and how to calibrate the device Developing Your Application This section describes the software and programming steps necessary to use the NI PXI 4224 For more informat
9. jndupBoeuy 1066u Oo S A t f vgl d dull 3 Jonuo Iv 2 WNOudaa Le BOES eoeyeiul eoeneiu sng Sta sng K Ed Qum 0d oueuet WOHdaa Seele SNS 77 puoo euis D joule N uoneinBiuo5 n vv P Josues duet XAN la all r XNW M H soxeidainwy idu 4 Odla E epo Le Bojeuy COM QN Lal Bojeuy L Le La Jed sovauomeuqeo Le apoio Jet sod oido lt dwy OSI Uonoeioid vod wu 44V Dome Midd indul 91V Uonoeiod VOd indul r siv onoelold Vod gy 4v onoelold Hd ndu ev Uonoeloid VOd wu av Uonoeloid Vod gy E HY Uonoeijod vod gy 40V Figure 4 1 Block Diagram of NI PXI 4224 ni com 4 2 NI PXI 4224 User Manual Chapter 4 Theory of Operation Signal Conditioning Functional Overview The NI PXI 4224 is part of the PXI 4200 series of DAQ devices with integrated signal conditioning designed to provide application specific signal conditioning DAQ and integrated field wiring connectivity on the same product The NI PXI 4224 signal conditioning circuitry is designed to provide attenuation amplification and filtering capabilities as described in Table 4 1 Table 4 1 Signal Conditioning Functional Blocks Signal Conditioning Component Description Input Protection Each NI PXI 4224 channel has overvoltage protection in the event that a channel is improperly wired PGA Each channel has a programmable gain amplif
10. ground referenced signal connection connecting to NI PXI 4224 2 12 H hardware overview timing signal routing device and PXI clocks 4 7 programmable function inputs 4 6 injector ejector handle position figure C 2 input impedance 4 3 Input Multiplexer figure 4 6 installation hardware 1 4 software 1 3 L LabVIEW software application development 5 5 DAQmx Channel Property Node 5 7 programming a task in LabVIEW table 5 6 synchronizing multiple devices 5 8 LED pattern descriptions 1 4 National Instruments Corporation F3 Index MAX See Measurement amp Automation Explorer MAX maximum working voltage specifications A 5 Measurement amp Automation Explorer MAX configuring NI PXI 4224 3 1 creating voltage task or global channel 3 2 removing NI PXI 4224 C 2 verifying installation 3 1 NI DAQmx Task or Global Channel 3 3 signal connections 3 1 measurement considerations common mode rejection ratio 4 4 effective CMR 4 5 input impedance 4 3 memory specifications A 3 National Instruments ADE software 5 1 NI PXI 4224 See also installation See also specifications block diagram of NI PXI 4224 4 2 calibrating 5 12 configuring 5 4 documentation 1 3 overview 1 1 requirements for getting started 1 2 software National Instruments ADE software 1 3 NI DAQ 1 3 theory of operation 4 1 block diagram of NI PXI 4224 4 2 device and PXI clocks 4 7 measurement considerations 4 3 pr
11. measurement To measure scaled voltages further configure channel properties and configure timing settings use an NI DAQmx Task or NI DAQmx Global Channel National Instruments Corporation 3 1 NI PXI 4224 User Manual Chapter 3 Configuring and Testing Configuring the NI PXI 4224 in MAX This section describes how to create NI DAQmx Tasks and NI DAQmx Global Channels in MAX that allow you to take measurements with the NI PXI 4224 Creating a Voltage Task or Global Channel Using NI DAQmx An NI DAQmx Global Channel gives a physical channel a name and provides scaling An NI DAQmx Task is a collection of channels with timing and triggering configured To create a new NI DAQmx Task or NI DAQmx Global Channel complete the following steps 1 9 Double click the Measurement amp Automation Explorer icon on the desktop Right click Data Neighborhood and select Create New Select NI DAQmx Task or NI DAQmx Global Channel and click Next Select Analog Input and select Voltage If you are creating a channel you can select only one channel If you are creating a task select the channels to add to the task You can select a range of channels by holding down the lt Shift gt key while selecting the channels You can select multiple individual channels by holding down the lt Ctrl gt key while selecting channels Click Next Enter the name of the task or channel and click Finish Select the channel s you want
12. Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The reader should consult National Instruments if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover damages defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner
13. NI PXI 4224 User Manual Read Me First Safety and Radio Frequency Interference DAQ Getting Started Guide PXI or PXI SCXI combination chassis user manual A Documentation for your software Tools 1 8 in flathead screwdriver You can download NI documents from ni com manuals NI PXI 4224 User Manual ni com Chapter 1 About the NI PXI 4224 National Instruments Documentation The NI PXI 4224 User Manual is one piece of the documentation set for your DAQ system You could have any of several types of manuals depending on the hardware and software in your system Use the manuals you have as follows e DAQ Getting Started Guide This document describes how to install NI DAQ devices and NI DAQ Install NI DAQmx before you install the SCXI module e SCXI Quick Start Guide This document describes how to set up an SCXI chassis install SCXI modules and terminal blocks and configure the SCXI system in MAX e PXIor PXI SCXI combination chassis manual Read this manual for maintenance information about the chassis and for installation instructions e Accessory installation guides or manuals If you are using accessory products read the terminal block installation guides They explain how to physically connect the relevant pieces of the system e Software documentation You may have both application software and NI DAQmx software documentation NI application software includes LabVIEW Measurement S
14. Signal Source Connection Using D SUB Connector tiet tet eie 2 7 Figure 2 6 Unshielded Floating Signal Source Connection Using a Terminal Block dett eter 2 8 Figure 2 7 Unshielded Grounded Signal Source Connection Using a Terminal Block ete etre eig 2 9 Figure 2 8 Shielded Floating Signal Source Connection Using a Terminal Block noe dete pee tete 2 10 Figure 2 9 Shielded Grounded Signal Source Connection Using a Terminal Block tg ENNEN 2 11 Figure 4 1 Block Diagram of NI PXI 4224 oie eeceseeeeceneceneeeeeeetnetsneeeeeenaee 4 2 Figure 4 2 Effect of Input Impedance on Signal Measurements 4 4 Figure 4 3 AI CONV CLK Signal Routing eene 4 6 Figure 4 4 NI PXI 4224 PXI Trigger Bus Signal Connection 4 8 Figure 5 1 Typical Program Flowchart eene 5 2 Figure 5 2 General Synchronizing Flowchart eese 5 9 Figure A 1 PXI 4224 Dimensions essere nennen nennen entente A 4 Figure BI Typical Posttriggered Sequence esee B 2 Figure B 2 Typical Pretriggered Sequence B 2 Figure B 3 AI START TRIG Input Signal Timing eee B 3 Figure BA AI START TRIG Output Signal Timing eee B 3 Figure BA AI REF TRIG Input Signal Tmmg eee B 4 Figure B 6 AI REF TRIG Output Signal Timing eee B 5 Figure B 7 AI SAMP CLK Input
15. application National Instruments Corporation LabVIEW Example Programs available by selecting Help Find Examples from the opening screen Most of the examples applicable to the NI PXI 4224 are located in Hardware Input and Output DAQmx Analog Measurements and Hardware Input and Output DAQmx Synchronization Multi Device PXI 4224 Supported Properties in the LabVIEW VI Function amp How To Help Application Note 025 Field Wiring and Noise Considerations for Analog Signals available at ni com info using the info code rdfwn3 5 11 NI PXI 4224 User Manual Chapter 5 Using the NI PXI 4224 Calibrating the NI PXI 4224 Calibration refers to the process of minimizing measurement errors On the NI PXI 4224 errors from the digitizer components of the DAQ device circuitry are corrected in the analog circuitry by onboard calibration digital to analog converters CalDACs Errors from the signal conditioning circuitry are corrected in software Three levels of calibration are available for the NI PXI 4224 to ensure the accuracy of its analog circuitry The first level loading calibration constants is the fastest easiest and least accurate The NI PXI 4224 automatically loads calibration constants stored in flash memory when powered on The intermediate level internal calibration is the preferred method for assuring accuracy in your application The last level external calibration is the slowest most difficult and mo
16. channel isolated analog input device with a X10 V input range It allows isolated analog measurements directly on the PXI platform The NI PXI 4224 has the following characteristics e Each channel has a gain of either 1 or 10 e An isolation rating of 42 4 V peak or 60 VDC Category I e The front connector is a 25 pin D SUB connector with 16 pins for analog input Signal connections are made through a TB 2725 terminal block that provides connections for all eight analog input channels You can optionally connect a standard 25 pin D SUB cable to the device and cable it as needed for your application iyi Note Go to ni com products to determine if newly developed terminal blocks are available You can configure most settings on a per channel basis through software The NI PXI 4224 is configured using Measurement amp Automation Explorer MAX or through function calls to NI DAQmx ei Note The NI PXI 4224 is supported in NI DAQmx only National Instruments Corporation 1 1 NI PXI 4224 User Manual Chapter 1 About the NI PXI 4224 What You Need to Get Started To set up and use the NI PXI 4224 you need the following Hardware NIPXI 4224 One of the following e TB 2725 terminal block e 25 pin D SUB female connector PXI or PXI SCXI combination chassis Software NI DAQ 7 3 1 or later Oneofthe following LabVIEW e Measurement Studio e LabWindows CVI Documentation
17. decide whether to create the task using the DAQ Assistant or programmatically in the ADE Developing your application using NI DAQmx allows you to configure most settings such as measurement type selection of channels input limits task timing and task triggering using the DAQ Assistant tool You can access the DAQ Assistant either through MAX or through your NI ADE Choosing to use the DAQ Assistant can simplify the development of your application When using a sensor that requires complex scaling or when many properties differ between channels in the same task NI recommends creating tasks using the DAQ Assistant for ease of use If you are using an ADE other than an NI ADE or if you want to explicitly create and configure a task for a certain type of acquisition you can programmatically create the task from your ADE using function or VI calls If you create a task using the DAQ Assistant you can still further configure the individual properties of the task programmatically using function calls or property nodes in your ADE NI recommends creating a task programmatically if you need explicit control of programmatically adjustable properties of the DAQ system Programmatically creating tasks is also recommended if you are synchronizing multiple devices using master and slave tasks Programmatically adjusting properties for a task created in the DAQ Assistant overrides the original settings only for that session The changes are not saved t
18. display the list of NI DAQmx devices 5 12 ni com Chapter 5 Using the NI PXI 4224 4 Right click the NI PXI 4224 and select Self Calibrate A dialog box opens indicating that the NI PXI 4224 is self calibrating 6 When the dialog box closes the NI PXI 4224 is successfully self calibrated EI Note The NI PXI 4224 also can be self calibrated programmatically by using DAQmx Self Calibrate vi in LabVIEW The results of an internal calibration are stored in the NI PXI 4224 flash memory so that the CalDACs are automatically loaded with the newly calculated calibration constants the next time the NI PXI 4224 is powered on Performing a self calibration at the operating temperature of your application will ensure the NI PXI 4224 meets the specifications in Appendix A Specifications External Calibration You can download all available external calibration documents by going to ni com calibration and clicking Manual Calibration Procedures NI recommends you perform an external calibration once a year National Instruments Corporation 5 13 NI PXI 4224 User Manual Specifications This appendix lists the specifications for the NI PXI 4224 device These specifications are typical at 25 C unless otherwise noted Overvoltage Protection Analog Input Powered on or oft 42 4 V peak or 60 VDC max PFI 0 CAL SMB connector 15 V powered on or off Number of input channels 8 Input rang
19. method Synchronizing the NI PXI 4224 NI PXI 4224 User Manual Figure 5 2 shows a typical program flowchart for synchronizing the sample clocks and start triggers of two devices taking a measurement and clearing the data 5 8 ni com Chapter 5 Using the NI PXI 4224 Create a Master Task optional Y Create Master Configure Slave Timing Al Voltage Channels y Set Slave to Use Configure Master i Timebase from Master Channel y Configure Master Timing Configure Slave Triggering y Start Slave Measurement s Get Master Timebase Source and Rate from Master Task Create a Slave Task optional Start Master Measurement Create Slave Al Voltage Channels Read Measurement Configure Slave Channel Continue Sampling More Slave Tasks Clear Master Task Clear Slave Task Figure 5 2 General Synchronizing Flowchart National Instruments Corporation 5 9 NI PXI 4224 User Manual Chapter 5 Using the NI PXI 4224 Synchronizing the NI PXI 4224 Using LabVIEW This section describes in more detail the steps shown in Figure 5 2 such as how to create a task in LabVIEW and configure the channels of the NI PXI 4224 For further instructions select Help VI Function amp How To Help from the LabVIEW menu bar Note Except where otherwise stated the VIs in Table 5 3 are located on the Functions All F
20. mmm CX NI PXI 4224 User Manual Figure 2 2 Unshielded Floating Signal Source Connection Using a D SUB Connector ni com Chapter 2 Connecting Signals Signal Source Vaig Ground Reference Twisted Pair Wiring CHO AlO p AlO e e e CH7 Al 7 AI 7 Figure 2 3 Unshielded Grounded Signal Source Connection Using a D SUB Connector National Instruments Corporation 2 5 NI PXI 4224 User Manual Chapter 2 Connecting Signals Signal Source Shielding Twisted Pair AlO AIO Al 7 Al 7 CH 0 HU CH NI PXI 4224 User Manual Figure 2 4 Shielded Floating Signal Source Connection Using a D SUB Connector 2 6 ni com Chapter 2 Connecting Signals Twisted Pair Signal Source Shielding Wiring EH AIO e e Vae Ground Reference CH7 ae ee ALT H Al7 Figure 2 5 Shielded Grounded Signal Source Connection Using a D SUB Connector National Instruments Corporation 2 7 NI PXI 4224 User Manual Chapter 2 Connecting Signals Figures 2 6 through 2 9 illustrate connecting signals using a terminal block Terminal Block l I Twisted Pair CHO Wiring ALO Be gt Vse Abo s Ge CH7 Al7 Q _ AL7 pm gt
21. normally green and blinks yellow for a minimum of 100 ms during the NI PXI 4224 configuration e The ACTIVE LED is normally green and blinks yellow for a minimum of 100 ms during data acquisition NI PXI 4224 User Manual 1 4 ni com Connecting Signals This chapter provides details about the front signal connector of the NI PXI 4224 and how to connect signals to the NI PXI 4224 Connecting Signals to the NI PXI 4224 After you have verified that the NI PXI 4224 is installed correctly and self tested the device refer to the following sections to connect signals to the device UN Caution Refer to the Read Me First Safety and Radio Frequency Interference document before removing equipment covers or connecting or disconnecting any signal wires Front Signal Connector The NI PXI 4224 connection interface consists of a 25 pin D SUB connector and one SMB connector You can program SMB connector as a PFI 0 line or for external calibration Table 2 1 shows the signal assignments of the D SUB connector for the NI PXI 4224 Figure 2 1 shows the front label with each set of screw terminals labeled according to the corresponding differential input signal for the NI PXI 4224 To connect a signal to the NI PXI 4224 use a TB 2725 terminal block designed specifically for the NI PXI 4224 or use a 25 pin D SUB to build a connector to suit your application Refer to the TB 2725 Terminal Block Installation Guide if you are using the TB 2725 te
22. s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside reasonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation National Instruments respects the intellectual property of others and we ask our users to do the same NI software is protected by copyright and other intellectual property laws Where NI software may be used to reproduce software or other materials belonging to others you may use NI software only to reproduce materials that you may reproduce in accordance with the terms of any applicable license or other legal restriction Trademarks National Instruments NI ni com and LabVIEW are trademarks of National Instruments Corporation Refer to the Terms of Use section on ni com 1egal for more information about National Instruments trademarks Other product and company names mentioned herein are trademarks or trade names of their respective companies Patents For patents covering National Instruments products technology refer to the appropriate location Help Patents in your software the patents txt file on your media or the National Instrume
23. set to high impedance at startup Figures B 5 and B 6 show the input and output timing requirements for AI REF TRIG Rising Edge Polarity Falling Edge Polarity ty 10 ns minimum Figure B 5 Al REF TRIG Input Signal Timing B 4 ni com Appendix B Timing Signal Information ty 50 to 100 ns Figure B 6 Al REF TRIG Output Signal Timing Al SAMP CLK Signal The AI SAMP CLK signal can be externally input from PFI 0 PXI Trig 0 5 or PXI Star It can be output on any PXI trigger bus line Refer to Figures B 1 and B 2 for the relationship of AI SAMP CLK to the sequence Asaninput AI SAMP CLK is configured in edge detection mode You can configure the polarity selection for either rising or falling edge The selected edge of AI SAMP CLK initiates a scan The SI2 counter starts if you select an internally triggered AI CONV CLK As an output AI SAMP CLK reflects the actual start pulse that initiates a scan even if the starts are externally triggered by another PFI or PXI Trig 0 5 Two output options are available The first option is an active high pulse with a pulse width of 50 to 100 ns which indicates the start of the scan The second option is an active high pulse that terminates at the start of the last conversion in the scan which indicates a scan in progress AI SAMP CLK is deasserted Lo after the last conversion in the scan is initiated This output is set
24. D TEAR RoHS XT National Instruments F E RoHS HH iE Ho WPG3tni com environment rohs china For information about China RoHS compliance go to ni com environment rohs china National Instruments Corporation A 7 NI PXI 4224 User Manual Timing Signal Information This appendix contains additional information about the timing signals discussed in Chapter 4 Theory of Operation Connecting Timing Signals Caution Exceeding the maximum input voltage ratings listed in Appendix A Specifications can damage the device and the computer NI is not liable for any damage resulting from such signal connections Programmable Function Input Connections You can externally control seven internal timing signals from PFI 0 and the PXI trigger bus pins The source for each of these signals is software configurable from PFI 0 PXI Trig 0 5 or PXI Star when you want external control This flexible routing scheme reduces the need to change the physical wiring to the device I O connector for applications requiring alternative wiring As an input each PFI signal can be individually configured for edge or level detection and polarity selection You can use the polarity selection for any timing signal but the edge or level detection depends on the particular timing signal being controlled The detection requirements for each timing signal are listed in the corresponding secti
25. E signal description table 4 9 overview B 10 signal timing figure B 10 AI PAUSE TRIG signal description table 4 9 overview B 8 NI PXI 4224 User Manual l 2 AI REF TRIG signal input signal timing figure B 4 output signal timing figure B 5 overview B 4 AI SAMP CLK signal input signal timing figure B 6 output signal timing figure B 6 overview B 5 AI SAMPLE CLK TIMEBASE signal description table 4 9 overview B 9 signal timing figure B 9 AI START TRIG signal description table 4 9 input signal timing figure B 3 output signal timing figure B 3 overview B 3 posttriggered sequence figure B 2 pretriggered sequence figure B 2 typical posttriggered acquisition figure B 2 typical pretriggered acquisition figure B 2 DAQmx Channel Property Node using in LabVIEW 5 7 developing applications See application development device and PXI clocks 4 7 digital trigger specifications A 3 documentation application development 5 11 conventions used in the manual iv National Instruments documentation 1 3 E effective CMR 4 5 electromagnetic compatibility specifications A 6 environmental specifications A 5 external calibration 5 13 D 2 ni com F floating signal source connection connecting to NI PXI 4224 2 11 front signal connector 2 1 front label of NI PXI 4224 figure 2 3 signal assignments of NI PXI 4224 table 2 2 G global channel creating 3 2 verifying 3 3
26. PXI NI PXI 4224 User Manual August 2008 lt 7 NATIONAL eiie ANiNsrRUMENTS Worldwide Technical Support and Product Information ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 683 0100 Worldwide Offices Australia 1800 300 800 Austria 43 662 457990 0 Belgium 32 0 2 757 0020 Brazil 55 11 3262 3599 Canada 800 433 3488 China 86 21 5050 9800 Czech Republic 420 224 235 774 Denmark 45 45 76 26 00 Finland 358 0 9 725 72511 France 01 57 66 24 24 Germany 49 89 7413130 India 91 80 41190000 Israel 972 3 6393737 Italy 39 02 41309277 Japan 0120 527196 Korea 82 02 3451 3400 Lebanon 961 0 1 33 28 28 Malaysia 1800 887710 Mexico 01 800 010 0793 Netherlands 31 0 348 433 466 New Zealand 0800 553 322 Norway 47 0 66 90 76 60 Poland 48 22 3390150 Portugal 351 210 311 210 Russia 7 495 783 6851 Singapore 1800 226 5886 Slovenia 386 3 425 42 00 South Africa 27 0 11 805 8197 Spain 34 91 640 0085 Sweden 46 0 8 587 895 00 Switzerland 41 56 2005151 Taiwan 886 02 2377 2222 Thailand 662 278 6777 Turkey 90 212 279 3031 United Kingdom 44 0 1635 523545 For further support information refer to the Signal Conditioning Technical Support Information document To comment on National Instruments documentation refer to the National Instruments Web site at ni com info and enter the info code feedback 2004 2008 National Instruments Corporation All rights
27. Signal Timing eee B 6 Figure B 8 AI SAMP CLK Output Signal Timing eee B 6 Figure BO AI CONV CLK Input Signal Timing eee B 7 Figure B 10 AI CONV CLK Output Signal Timing eee B 8 Figure B 11 AI SAMPLE CLK TIMEBASE Signal Timing eeeeeeeeeeeeereeeree B 9 Figure B 12 AI HOLD COMPLETE Signal Timing eee B 10 Figure C 1 Injector Ejector Handle Position Before Device Removal C 2 National Instruments Corporation vii NI PXI 4224 User Manual Contents Tables Table 2 1 NI PXI 4224 25 Pin D SUB Terminal Pin Assignments 2 2 Table 4 1 Signal Conditioning Functional Blocks esses 4 3 Table 4 2 PXI Trigger Bus Timing Signals eee 4 9 Table 5 1 NI DAQmx Properties essent 5 4 Table 5 2 Programming a Task in LabVIEW sse 5 6 Table 5 3 Synchronizing the NI PXI 4224 Using LabVIEW seeen 5 10 Table A 1 Maximum Sampling Rates A A 1 NI PXI 4224 User Manual viii ni com About the NI PXI 4224 This chapter provides an introduction to the NI PXI 4224 device and its installation The NI PXI 4224 is part of the NI PXI 4200 series of data acquisition DAQ devices with integrated signal conditioning The PXI 4200 series reduces measurement setup and configuration complexity by integrating signal conditioning and DAQ on the same product The NI PXI 4224 is an 8
28. TEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION Conventions 3 A A N bold italic monospace The following conventions are used in this manual Angle brackets that contain numbers separated by an ellipsis represent a range of values associated with a bit or signal name for example AO lt 3 0 gt The symbol leads you through nested menu items and dialog box options to a final action The sequence File Page Setup Options directs you to pull down the File menu select the Page Setup item and select Options from the last dialog box This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is marked on the product refer
29. ally consist of either four or eight digital channels The clock controlling the time interval between individual channel sampling within a scan G 2 ni com CMR CMRR common mode signal counter timer D D A D GND DAC DAQ DAQ Assistant DAQ STC dB DC differential input DIO dithering National Instruments Corporation G 3 Glossary Common mode rejection Common mode rejection ratio A measure of an instrument s ability to reject interference from a common mode signal usually expressed in decibels dB Any voltage present at the instrumentation amplifier inputs with respect to amplifier ground A circuit that counts external pulses or clock pulses timing Digital to analog Digital ground signal Digital to analog converter An electronic device often an integrated circuit that converts a digital number into a corresponding analog voltage or current Data acquisition 1 Collecting and measuring electrical signals from sensors transducers and test probes or fixtures and inputting them to a computer for processing 2 collecting and measuring the same kinds of electrical signals with A D and or DIO devices plugged into a computer and possibly generating control signals with D A and or DIO devices in the same computer A configuration assistant with which you define and configure your DAQ operation Data acquisition system timing controller chip Decibel The unit f
30. alog input multiplexers that indicate when the input signal has been sampled and can be removed This signal has a 400 to 500 ns pulse width and is software enabled Figure B 12 shows the timing for AI HOLD COMPLETE programmed using NI DAQmx It is a positive polarity pulse NI PXI 4224 User Manual AI CONV CLK AI HOLD COMPLETE a Lu gt lt tw ty 50 to 100 ns ty 400 to 500 ns Figure B 12 Al HOLD COMPLETE Signal Timing B 10 ni com Removing the NI PXI 4224 This appendix provides details for removing an NI PXI 4224 device from MAX and from a PXI or PXI SCXI combination chassis iyi Note You must physically remove the NI PXI 4224 from the chassis before you can remove it from MAX Removing the NI PXI 4224 from a PXI or PXI SCXI Combination Chassis Consult the PXI or PXI SCXI chassis documentation for additional instructions and cautions To remove the NI PXI 4224 device from a PXI or PXI SCXI chassis complete the following steps while referring to Figure C 1 1 Power off the PXI chassis Do not remove the NI PXI 4224 device from a chassis that is powered on If the you are using a PXI SCXI combination chassis also power off the SCXI portion of the chassis 2 Rotate the mounting screws that secure the NI PXI 4224 to the chassis counter clockwise until they are loose but do not completely remove the screws 3 Remove the NI PXI 4224 by pushing down steadi
31. an existing property and left click Add Element To change the new property left click it and select the property you wish to define You can also drag the bottom of the property node down to add more channels to the node iyi Note Refer to the LabVIEW Help for information about property nodes and specific NI DAQmx properties Synchronization and Triggering If you have multiple NI PXI 4224 devices you can synchronize them to acquire samples at the same time and at the same rate You can use multiple NI PXI 4224 devices to acquire and analyze complex signals For multiple NI PXI 4224 devices to start an acquisition simultaneously they all must reference a common start trigger To prevent drift over the course of the acquisition they must share a common timebase or sample clock The NI PXI 4224 that generates the start trigger and the timebase for all of the synchronized devices is called the master The master NI PXI 4224 exports the shared timing signals through the PXI bus to the slave devices Each NI PXI 4224 contains a DAQ STC chip that is capable of generating a hardware sample clock based on its timebase clock and start trigger This causes the slave device to acquire samples at the same time as the master The preferred method of synchronization is to use a shared timebase but it is also possible to synchronize multiple NI PXI 4224 devices by sharing the sample clock between them This manual only discusses the shared timebase
32. ations A 1 application development acquiring data 5 5 adjusting timing and triggering 5 3 analyzing data 5 5 clearing tasks and memory 5 5 configuring channel properties 5 4 creating tasks programmatically 5 3 using DAQ Assistant 5 3 documentation 5 11 example programs note 5 1 presenting data 5 5 synchronizing multiple devices overview 5 8 program flow chart figure 5 9 using LabVIEW 5 10 typical program flow chart 5 1 using LabVIEW 5 5 DAQmx Channel Property Node 5 7 steps table 5 6 block diagram of the NI PXI 4224 4 2 calibration external calibration 5 13 loading calibration constants 5 12 NI PXI 4224 User Manual Index pre calibration errors A 3 self calibration 5 12 specifications A 3 CE compliance specifications A 6 channel properties configuring in application development table 5 4 in LabVIEW 5 7 clocks PXI 4 7 See also DAQ timing connections See also PXI trigger bus common questions D 1 common mode rejection CMR effective 4 5 common mode rejection ratio CMRR 4 4 configuring channel properties in application development table 5 4 in LabVIEW 5 7 NI PXI 4224 in MAX 3 2 overview 3 1 connecting signals See signal connections conventions used in the manual iv D DAQ Assistant 5 3 DAQ timing connections AI CONV CLK signal input signal timing figure B 7 output signal timing figure B 8 overview B 7 signal routing figure 4 6 AI HOLD COMPLET
33. attery A floating signal source is not connected in any way to the building ground system To connect a floating signal source connection to the NI PXI 4224 the signal Vs g is connected to the NI PXI 4224 channel AI X The signal reference Vs g is connected to the channel reference AI X NI PXI 4224 User Manual Chapter 2 Connecting Signals NI PXI 4224 User Manual Ground Referenced Signal Connection Figures 2 3 2 5 2 7 and 2 9 illustrate the ground referenced signal connection In this configuration the voltage source being measured is referenced to its own ground reference that is connected through a conductive path to the instrument ground reference For example the path can be through a common earth ground or through the power line ground To connect a ground reference signal source to the NI PXI 4224 the signal Vsig is connected to the NI PXI 4224 channel AI X The signal reference Vs g is connected to the channel reference AI X Shielded Ground Referenced Signal Connection Recommended Figures 2 5 and 2 9 illustrate shielded ground referenced signal connections The connection to this signal source is identical to the ground referenced signal connection with the addition of shielding around the field wiring The shielding is grounded at the signal source ground Mac Ground Reference Connect the signal Mack to the NI PXI 4224 channel AI X Connect the signal reference Vsj5
34. ce can be gated by either the hardware AI PAUSE TRIG signal or the software command register gate AI CONV CLK Signal PFI 0 PXI_Trig lt 0 5 gt or PXI Star can externally input the AI CONV CLK signal which is also available as an output on PXI Trig 0 5 or PXI Star Refer to Figures B 1 and B 2 for the relationship of AI CONV CLK to the sequence As an input AI CONV CLK is configured in edge detection mode You can configure the polarity selection for either rising or falling edge The selected edge of AI CONV CLK initiates an A D conversion As an output AI CONV CLK reflects the actual convert pulse that connects to the ADC even if the conversions are externally generated by another PFI The output is an active low pulse with a pulse width of 50 to 100 ns This output is set to high impedance at startup Figures B 9 and B 10 show the input and output timing requirements for AI CONV CLK lt ty gt Rising Edge Polarity Falling Edge Polarity ty 10 ns minimum Figure B 9 Al CONV CLK Input Signal Timing National Instruments Corporation B 7 NI PXI 4224 User Manual Appendix B Timing Signal Information NI PXI 4224 User Manual ty 50 to 100 ns Figure B 10 Al CONV CLK Output Signal Timing The ADC switches to hold mode within 60 ns of the selected edge This hold mode delay time is a function of temperature and does not vary from one conversion to the ne
35. clock produces one scan which acquires one new sample from every analog input channel in the group The clock controlling the time interval between scans Controls how often a scan is initialized The scan interval is regulated by AI SAMP CLK Reciprocal of the scan interval G 8 ni com SCXI self calibrating signal conditioning software trigger STC T TRIG trigger TTL VDC VI VMEAS rms National Instruments Corporation G 9 Glossary Signal Conditioning eXtensions for Instrumentation The NI product line for conditioning low level signals within an external chassis near sensors so only high level signals are sent to DAQ devices in the noisy PC environment A property of a DAQ device that has an extremely stable onboard reference and calibrates its own A D and D A circuits without manual adjustments by the user The manipulation of signals to prepare them for digitizing A programmed event that triggers an event such as DAQ System timing controller Trigger signal Any event that causes or starts some form of data capture Transistor transistor logic A digital circuit composed of bipolar transistors wired in a certain manner Volt or volts Volts direct current Virtual instrument 1 A combination of hardware and or software elements typically used with a PC that has the functionality of a classic stand alone instrument 2 a LabVIEW software device VI which consists of a fron
36. e eme 10 VDC Resol tion eere etes 16 bits Maximum sampling rate 200 kS s aggregate multichannel Table A 1 Maximum Sampling Rates Number of Channels Sample Rate 1 333 kS s 2 100 0 kS s ch 3 66 6 kS s ch 4 50 0 kS s ch 5 40 0 kS s ch 6 33 3 kS s ch 7 28 5 kS s ch 8 25 0 kS s ch National Instruments Corporation A 1 NI PXI 4224 User Manual Appendix A Specifications for Input coupling eee DC Bandwidth 3 dB o oo 15 kHz SEW TAL itte bt ee 2 V us typical Input impedance Powered on 100 MQ parallel 100 pF Powered off sss 30 KQ Input bias ceutent esses 100 pA CMRR Balanced eee de 120 dB at DC to 60 Hz 10 KQ imbalanced 85 dB at DC to 60 Hz 65 dB at 60 Hz to 10 kHz Crosstalk at 1 KHz Adjacent channels 15 dB All other channels 90 dB Accuracy Noise Quantization Absolute uV Temperature Drift Accuracy Nominal of at Full Range Reading Offset Single Gain Offset Scale V 1 Year uV Pt Averaged C u V C mV 10 V 0 11 1730 6317 200 0 0025 230 12 6 1V 0 12 176 632 20 0 0 0025 26 1 4 Note Accuracies are valid for measurements following an internal calibration and with autozero enabled and are listed for operational temperatures within 1 C of the interna
37. ement Category I Withstand rere 1400 Nun verified by a 5 s dielectric withstand type test Environmental Operating em perature 0 to 55 C Storage temperature sss 40 to 70 C ES out HE 10 to 90 RH noncondensing Maximum altitude sss 2 000 m Pollution Degree indoor use only 2 National Instruments Corporation A 5 NI PXI 4224 User Manual Appendix A Specifications for Safety This product meets the requirements of the following standards of safety for electrical equipment for measurement control and laboratory use IEC 61010 1 EN 61010 1 UL 61010 1 CSA 61010 1 hy Note For UL and other safety certifications refer to the product label or the Online Product Certification section Electromagnetic Compatibility This product meets the requirements of the following EMC standards for electrical equipment for measurement control and laboratory use EN 61326 IEC 61326 Class A emissions Basic immunity EN 55011 CISPR 11 Group 1 Class A emissions AS NZS CISPR 11 Group 1 Class A emissions FCC 47 CFR Part 15B Class A emissions ICES 001 Class A emissions B Note For the standards applied to assess the EMC of this product refer to the Online Product Certification section Ei Note For EMC compliance operate this product according to the documentation 3 Note For EMC compliance operate this device with shielded cables CE Compliance C This product meets the ess
38. ential requirements of applicable European Directives as follows 2006 95 EC Low Voltage Directive safety 2004 108 EC Electromagnetic Compatibility Directive EMC Online Product Certification Refer to the product Declaration of Conformity DoC for additional regulatory compliance information To obtain product certifications and the DoC for this product visit ni com certification search by model number or product line and click the appropriate link in the Certification column NI PXI 4224 User Manual A 6 ni com Appendix A Specifications for Environmental Management NI is committed to designing and manufacturing products in an environmentally responsible manner NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers For additional environmental information refer to the NI and the Environment Web page at ni com environment This page contains the environmental regulations and directives with which NI complies as well as other environmental information not included in this document Waste Electrical and Electronic Equipment WEEE K EU Customers At the end of the life cycle all products must be sent to a WEEE recycling center For more information about WEEE recycling centers and National Instruments WEEE initiatives visit ni com environment weee AF Ra mis Risa SED ChE ROHS SU PHA National Instruments Kett Ere FE ALP PB BEF EES E
39. equence NI PXI 4224 User Manual B 2 ni com Appendix B Timing Signal Information Al START TRIG Signal The AI START TRIG signal can be input or output through PFI 0 PXI_Trig lt 0 5 gt or PXI Star As an input AI START TRIG is configured in the edge detection mode You can select PFI 0 as the source for AI START TRIG and configure the polarity selection for either rising or falling edge The selected edge of AI START TRIG starts the sequence for both posttriggered and pretriggered acquisitions Refer to Figures B 1 and B 2 for the relationship of AI START TRIG to the sequence As an output AI START TRIG reflects the action that initiates a sequence even if the acquisition is externally triggered by another PFI The output is an active high pulse with a pulse width of 50 to 100 ns This output is set to high impedance at startup Figures B 3 and B 4 show the input and output timing requirements for AI START TRIG Rising Edge Polarity Falling Edge Polarity ty 10 ns minimum Figure B 3 Al START TRIG Input Signal Timing ty 50 to 100 ns Figure B 4 Al START TRIG Output Signal Timing National Instruments Corporation B 3 NI PXI 4224 User Manual Appendix B Timing Signal Information NI PXI 4224 User Manual The device also uses AI START TRIG to initiate pretriggered operations In pretriggered applications AI START TRIG is generated by a software trigger unless a PFI
40. f the PXI chassis for precise synchronization of functions This bus is functionally equivalent to the RTSI bus for PCI DAQ devices NI PXI 4224 User Manual Glossary R relative accuracy resolution rms RTSI bus S s sample counter scan scan clock scan interval Scan rate NI PXI 4224 User Manual A measure in LSB of the accuracy of an ADC It includes all nonlinearity and quantization errors It does not include offset and gain errors of the circuitry feeding the ADC The smallest signal increment that can be detected by a measurement system Resolution can be expressed in bits in proportions or in percent of full scale For example a system has 16 bit resolution one part in 65 536 resolution and 0 0015 of full scale Root mean square The square root of the average value of the square of the instantaneous signal amplitude a measure of signal amplitude Real time system integration bus The NI timing bus that connects DAQ devices directly for precise synchronization of functions Second or seconds Sample or samples Samples per second Used to express the rate at which a DAQ device samples an analog signal The clock that counts the output of the channel clock in other words the number of samples taken One or more analog or digital input samples Typically the number of input samples in a scan is equal to the number of channels in the input group For example one pulse from the scan
41. g DAQmx Timing vi Sample Clock by default NI PXI 4224 User Manual 5 10 ni com Chapter 5 Using the NI PXI 4224 Table 5 3 Synchronizing the NI PXI 4224 Using LabVIEW Continued Flowchart Step VI or Program Step Set Slave to Use Timebase from Master Use a DAQmx Timing Property Node to set MasterTimebase Src and MasterTimebase Rate to the values retrieved from the master task in the Get Master Timebase Source and Rate from Master Task step Configure Slave Triggering DAQmx Trigger vi Start Digital Edge use MasterDevice ai StartTrigger as the source substituting the master device identifier for MasterDevice Start Slave Measurement s DAQmx Start Task vi Start Master Measurement DAQmx Start Task vi Read Measurement DAQmx Read vi Continue Sampling For continuous sampling use a While Loop You also need to set the sample mode to Continuous Samples in the Configure Master Timing and Configure Slave Timing steps To do this right click the terminal of the DAQmx Timing vi labeled sample mode and click Create Constant Click the checkbox and select Continuous Samples Clear Master Task DAQmx Clear Task vi Clear Slave Task DAQmx Clear Task vi Other Application Documentation and Material The following locations provide more information that you may find useful when setting up or connecting signal sources or programming your
42. his step is optional if you created and fully configured the channels in your task using the DAQ Assistant Start Measurement DAQmx Start Task vi Read Measurement DAQmx Read vi Analyze Data Some examples of data analysis include filtering scaling harmonic analysis or level checking Some data analysis tools are located on the Functions Signal Analysis subpalette and on the Functions All Functions Analyze subpalette Display Data You can use graphical tools such as charts gauges and graphs to display your data Some display tools are located on the Controls Numeric Indicators subpalette and Controls All Controls Graph subpalette NI PXI 4224 User Manual 5 6 ni com Chapter 5 Using the NI PXI 4224 Table 5 2 Programming a Task in LabVIEW Continued Flowchart Step VI or Program Step Continue Sampling For continuous sampling use a While Loop If you are using hardware timing you also need to set the DAQmx Timing vi sample mode to Continuous Samples To set the VI right click the terminal of the DAQmx Timing vi labeled sample mode and click Create Constant Click the box and select Continuous Samples Stop Measurement DAQmx Stop Task vi tThis VI is optional Clearing the task will automatically stop the task Clear Task DAQmx Clear Task vi Using a DAQmx Channel Property Node in LabVIEW You can use property nodes in LabVIEW to manually c
43. ier The available gains on the NI PXI 4224 are 1 and 10 which covers the input range of x1 V to 10 V The DAQ device can provide a gain of up to 200 in order to maximize the ADC resolution for signals below 1 V Isolation Amplifier Each channel has an isolation amplifier that creates true channel to channel isolation Post Filter A post filter is provided to clean up noise spikes created by the isolation amplifier Measurement Considerations This section provides more information about the type of signal connection made to the NI PXI 4224 and important factors that can affect your measurement Input Impedance Figure 4 2 illustrates the input impedance of an NI PX1 4224 and its effect on the measurement of a circuit under test If you know the source impedance of the circuit under test you can correct for the attenuation caused by the NI PXI 4224 in software Since Ryy is relatively large 1 GQ it requires a large source impedance Ry to cause a significant change in the measured voltage Vurae In general a source impedance of less than 200 kQ does not interfere with the accuracy of the measurement For example a 200 kQ source impedance results in a 0 02 gain error National Instruments Corporation 4 3 NI PXI 4224 User Manual Chapter 4 Theory of Operation Signal Source Source Impedance Cin Measured Fin input Voltage 100T Impedance V pF MEAS
44. ing After configuring the task and channels you can start your acquisition read measurements analyze the data returned and display it according to the needs of your application Typical methods of analysis include digital filtering averaging data performing harmonic analysis applying a custom scale or adjusting measurements mathematically NI provides powerful analysis toolsets for each NI ADE to assist non programmers in performing advanced data analysis After you acquire the data and perform any required analysis it is useful to display the data in a graphical form or log it to a file NI ADEs provide easy to use tools for graphical display such as charts graphs slide rules and gauge indicators NI ADEs have tools that allow you to save the data to files such as spreadsheets for easy viewing ASCII files for universality or binary files for smaller file sizes Completing the Application After you have completed the measurement analysis and presentation of the data it is important to stop and clear the task This releases any memory used by the task and frees up the DAQ hardware for use in another task Developing an Application Using LabVIEW This section describes in more detail the steps shown in Figure 5 1 such as how to create a task in LabVIEW and configure the channels of the NI PXI 4224 For further instructions select Help VI Function amp How To Help from the LabVIEW menu bar ei Note Except where otherw
45. ion about a particular software or programming process refer to your ADE documentation Typical Program Flow Chart Figure 5 1 shows a typical program flow chart for creating an AI voltage channel taking a measurement and clearing the data Sy Note For more information about creating tasks and channels in MAX refer to Chapter 3 Configuring and Testing National Instruments Corporation 5 1 NI PXI 4224 User Manual Chapter 5 Using the NI PXI 4224 Create Task Using DAQ Assistant Create Task in DAQ Assistant or MAX Create a Task Programmatically Create Al Voltage Channel Further Configure Channels Hardware Timing Triggering No Configure Channels Adjust Timing Settings Analyze Data Display Data RTIA RTIA Tools 4 Start Measurement Read Measurement A Yes Continue Sampling YI Stop Measurement Clear Task Figure 5 1 Typical Program Flowchart NI PXI 4224 User Manual 5 2 ni com Chapter 5 Using the NI PXI 4224 Overview of Typical Flow Chart The following sections briefly discuss some considerations for some of the steps in Figure 5 1 These sections are meant to provide an overview of some of the options and features available when programming with NI DAQmx Creating a Task Using DAQ Assistant or Programmatically When creating an application you must first
46. ise stated the VIs in Table 5 2 are located on the Functions All Functions NI Measurements DAQm x Data Acquisition subpalette and accompanying subpalettes in LabVIEW National Instruments Corporation 5 5 NI PXI 4224 User Manual Chapter 5 Using the NI PXI 4224 Table 5 2 Programming a Task in LabVIEW Flowchart Step VI or Program Step Create Task in DAQ Assistant Create a Task Programmatically optional Create a DAQmx Task Name Constant located on the Controls All Controls I O DA Qmx Name Controls subpalette right click it and select New Task DAQ Assistant DAQmx Create Task vi located on Functions All Functions NI Measurements DA Qmx Data Acquisition DA Qmx Advanced Task Options This VI is optional if you created and configured your task using the DAQ Assistant However if you use it in LabVIEW any changes you make to the task will not be saved to a task in MAX Create AI Voltage Channel optional DAQmx Create Virtual Channel vi AI Voltage by default This VI is optional if you created and configured your task and channels using the DAQ Assistant Adjust Timing Settings optional DAQmx Timing vi Sample Clock by default This VI is optional if you created and configured your task using the DAQ Assistant Configure Channels optional DAQmx Channel Property Node Refer to the Using a DAQmx Channel Property Node in LabVIEW section for more information T
47. l Flow Chat 5 3 Creating a Task Using DAQ Assistant or Programmatically 5 3 Adjusting Timing and Triggering esee 5 3 Configuring Channel Properties eee 5 4 Acquiring Analyzing and Dresentmng 5 5 Completing the Application sese 5 5 Developing an Application Using LabVIEW sess 5 5 Using a DAQmx Channel Property Node in LabVIEW 5 7 Synchronization and Triggering seen 5 8 Synchronizing the NI PXI 4224 i petiini eerren oense eene 5 8 Synchronizing the NI PXI 4224 Using LabVIEW 5 10 Other Application Documentation and Material sesseeeeeeee 5 11 Calibrating the NI PXJA4224 nennen nennen enne nn ener 5 12 Loading Calibration Constante eese 5 12 Selt Calibration 5 need UD I ee Me etn ake 5 12 External Calibration osito re EM 5 13 Appendix A Specifications Appendix B Timing Signal Information Appendix C Removing the NI PXI 4224 Appendix D Common Questions Glossary Index NI PXI 4224 User Manual vi ni com Contents Figures Figure 2 1 NI PXI 4224 Front Label eese ene 2 3 Figure 2 2 Unshielded Floating Signal Source Connection Using a D SUB Connector eese 2 4 Figure 2 3 Unshielded Grounded Signal Source Connection Using a D SUB Connector eerte tei 2 5 Figure 2 4 Shielded Floating Signal Source Connection Using a D SUB Connector nenne 2 6 Figure 2 5 Shielded Grounded
48. l Functional Overview The NI PXI 4224 is based on the NI E Series DAQ device architecture This architecture uses the NI data acquisition system timing controller DAQ STC for time related functions The DAQ STC consists of two timing groups that control AI and general purpose counter timer functions These groups include a total of seven 24 bit and three 16 bit counters and a maximum timing resolution of 50 ns The DAQ STC makes possible applications such as equivalent time sampling and seamless changing of the sampling rate The NI PXI 4224 uses the PXI trigger bus to easily synchronize several measurement functions to a common trigger or timing event The PXI trigger bus is connected through the rear signal connector to the PXI chassis backplane The DAQ STC provides a flexible interface for connecting timing signals to other devices or external circuitry The NI PXI 4224 uses the PXI trigger bus to interconnect timing signals between PXI devices and the programmable function input PFI pin on the front SMB connector to connect the device to external circuitry These connections are designed to enable the device to both control and be controlled by other devices and circuits The DAQ STC has internal timing signals you can control by an external source These timing signals also can be controlled by signals internally generated to the DAQ STC and these signals are software configurable Figure 4 3 shows an example of the signal routing m
49. l calibration temperature and 10 C of 23 C Averaged numbers assume 1 000 single channel readings Transfer Characteristics Nonlinearity 0 0 0 eee eeeeseeseeeseeneeee 0 02 FSR DNE iEn 0 5 LSB typ 1 LSB max No missing code 16 bits guaranteed NI PXI 4224 User Manual A 2 ni com Calibration Recommended warm up time External calibration interval Pre Calibration Errors Pre calibration offset error relative to input RTI Signal conditioning component only Pre calibration gain error Signal conditioning component only Memory FIFO buffer size Data transfers DMA modes Digital Triggers Compatibility Appendix A Specifications for 865 mV max 50 mV typ 160 mV max at a gain of 1 18 900 ppm max 600 ppm typ 1 000 ppm max at a gain of 1 512 samples DMA interrupts programmed I O Scatter gather single transfer demand transfer 512 words Start and stop trigger gate clock PFI 0 AI START TRIG front SMB connector PXI_TRIG lt 0 5 gt to PXI Star PXI trigger bus 5 V TTL The pre calibration errors apply only to users doing register level programming Pre calibration errors are not visible to NI DAQmx users National Instruments Corporation A 3 NI PXI 4224 User Manual Appendix A Specifications for PXI Trigger Bus PCI Bus Interface RESPONSE PEE Rising or falling edge software programmable Pulse width
50. list within the scan interval The greater the interchannel delay the more time the PGA is allowed to settle before the next channel is sampled The interchannel delay is regulated by AI CONV CLK Kilo The standard metric prefix for 1 000 or 10 used with units of measure such as volts hertz and meters 1 000 samples NI PXI 4224 User Manual Glossary L LabVIEW LED linearity LSB MAX maximum working voltage MITE MSB mux NI PXI 4224 User Manual Laboratory Virtual Instrument Engineering Workbench A program development application based on the programming language G and used commonly for test and measurement purposes Light emitting diode The adherence of device response to the equation R KS where R response S stimulus and K a constant Least significant bit Measurement amp Automation Explorer NI software for configuring devices and channels The highest voltage with respect to ground that should be applied to an input terminal during normal use normally well under the breakdown voltage for safety margin Includes both the signal and common mode voltages MXI Interface to Everything A custom ASIC designed by NI that implements the PCI bus interface The MITE supports bus mastering for high speed data transfers over the PCI bus Most significant bit Multiplexer A switching device with multiple inputs that sequentially connects each of its inputs to its output
51. ly on the injector ejector handle until the device disengages from the chassis 4 Slide the device completely out The next time you restart the computer the NI PXI 4224 will have a red circle with a white X inside it next to the device in MAX National Instruments Corporation C 1 NI PXI 4224 User Manual Appendix C Removing the NI PXI 4224 Figure C 1 Injector Ejector Handle Position Before Device Removal Removing the NI PXI 4224 from MAX To remove an NI PXI 4224 device from MAX complete the following steps after launching MAX 1 Expand Devices and Interfaces to display the list of installed devices and interfaces The NI PXI 4224 should have a red circle with a white X inside it next to the device to indicate it has been physically removed from the chassis 2 Right click the NI PXI 4224 and click Delete 3 You are presented with a confirmation window Click Yes to continue deleting the device or No to cancel this action The NI PXI 4224 is now removed from the list of installed devices in MAX NI PXI 4224 User Manual C 2 ni com Common Questions This appendix lists common questions related to the use of the NI PXI 4224 Which version of NI DAQ works with the NI PXI 4224 and how do I get the most current version of NI DAQ You must have NI DAQ 7 3 1 or later and use NI DAQmx 1 Gotoni com 2 Follow the link Download Software Drivers and Updates
52. nce or system ground Also called nonreferenced signal sources Some common example of floating signal sources are batteries transformers or thermocouples Gram or grams The factor by which a signal is amplified sometimes expressed in decibels A measure of deviation of the gain of an amplifier from the ideal gain G 4 ni com I O in INL input bias current input impedance input offset current instrumentation amplifier interchannel delay kS National Instruments Corporation G 5 Glossary Hour or hours Hertz The number of scans read or updates written per second Input output The transfer of data to from a computer system involving communications channels operator interface devices and or DAQ and control interfaces Inch or inches Integral nonlinearity A measure in LSB of the worst case deviation from the ideal A D or D A transfer characteristic of the analog I O circuitry The current that flows into the inputs of a circuit The resistance and capacitance between the input terminals of a circuit The difference in the input bias currents of the two inputs of an instrumentation amplifier A circuit whose output voltage with respect to ground is proportional to the difference between the voltages at its two high impedance inputs Amount of time that passes between sampling consecutive channels The interchannel delay must be short enough to allow sampling of all the channels in the channel
53. ng Signal Information AI SAMPLE CLK TIMEBASE Signal PFI 0 PXI_Trig lt 0 5 gt or PXI Star can externally input the AI SAMPLE CLK TIMEBASE signal which is not available as an output on the I O connector The onboard scan interval SI counter uses AI SAMPLE CLK TIMEBASE as a clock to time the generation of the AI SAMP CLK signal Configure the pin you select as the source for AI SAMPLE CLK TIMEBASE in level detection mode Configure the polarity selection for the pin for either active high or active low The maximum allowed frequency is 20 MHz with a minimum pulse width of 23 ns high or low There is no minimum frequency Either the 20 MHz or 100 KHz internal timebase generates AI SAMPLE CLK TIMEBASE unless you select an external source Figure B 11 shows the timing requirements for AI SAMPLE CLK TIMEBASE ly tty e tp 50 ns minimum ty 23 ns minimum Figure B 11 Al SAMPLE CLK TIMEBASE Signal Timing National Instruments Corporation B 9 NI PXI 4224 User Manual Appendix B Timing Signal Information ER Note The polarity of AI HOLD COMPLETE is not software selectable when AI HOLD COMPLETE Signal AI HOLD COMPLETE is an output only signal that generates a pulse with the leading edge occurring approximately 50 to 100 ns after an A D conversion begins The polarity of this output is software configurable but the polarity is typically configured so that a low to high leading edge can clock external an
54. nnecting Signals Connecting Signals to the NI PXI 4224 sess eene ene 2 1 Front Signal Connector eic a eie de ignc 2 1 Analog Input Connections essent eee 2 3 Floating Signal Source Connection esee 2 11 Ground Referenced Signal Connection esee 2 12 Shielded Ground Referenced Signal Connection Recommended ai rere TN EIE 2 12 Chapter 3 Configuring and Testing Verifying and Self Testing the Signals Using Test Panels esses 3 1 Configuring the NI PXI 4224 in MAKE 3 2 Creating a Voltage Task or Global Channel Using NI DAQmx 3 2 Verifying and Self Testing an NI DAQmx Task or Global Channel 3 3 Chapter 4 Theory of Operation Theory of Operation 1e ere aee m ERR 4 1 Signal Conditioning Functional Overview sese 4 3 Measurement Considerations nennen 4 3 Input Impedance oie ree ecrire reda 4 3 Common Mode Rejection Rana 4 4 Effective CMR etie E RR ae ei eee 4 5 Timing and Control Functional Overview esee 4 5 Programmable Function Inputs eese en 4 6 Device and PXI Clocks utet edunt 4 7 National Instruments Corporation V NI PXI 4224 User Manual Contents Chapter 5 Using the NI PXI 4224 Developing Your Application esee a remet nemen enne 5 1 Typical Program Flow Chart 5 1 Overview of Typica
55. nts Patent Notice at ni com patents WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUSE SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT S
56. o the task configuration The next time you load the task the task uses the settings originally configured in the DAQ Assistant Adjusting Timing and Triggering There are several timing properties that you can configure either through the DAQ Assistant or programmatically using function calls or property nodes in your application If you create a task in the DAQ Assistant you still can modify the timing properties of the task programmatically in your application National Instruments Corporation 5 8 NI PXI 4224 User Manual Chapter 5 Using the NI PXI 4224 When programmatically adjusting timing settings you can set the task to acquire continuously acquire a buffer of samples or acquire one point at a time For continuous and buffered acquisitions you can set the acquisition rate and the number of samples to read By default the clock settings are automatically set by an internal clock based on the requested sample rate You also can select advanced features such as clock settings that specify an external clock source the internal routing of the clock source or that select the active edge of the clock signal You can also specify whether or not to start the acquisition using a start trigger signal Configuring Channel Properties All of the different ADEs used to configure the NI PXI 4224 access an underlying set of NI DAQmx properties Table 5 1 lists of some of the properties that configure the NI PXI 4224 You can use this li
57. ogrammable function inputs 4 6 NI PXI 4224 User Manual Index signal conditioning overview 4 3 timing and control overview 4 5 NI DAQ software 1 3 D 1 NI DAQmx channel properties configuring table 5 4 NI DAQmx Global Channel creating 3 2 verifying and self testing 3 3 NI DAQmx Task creating 3 2 verifying and self testing 3 2 0 operation theory See NI PXI 4224 overvoltage protection specifications A 1 P PCI bus interface A 4 PFI 0 CAL SMB connector 4 6 B 1 PFIs See programmable function inputs physical specifications A 4 posttriggered data acquisition overview B 2 typical acquisition figure B 2 power requirement specifications A 4 pretriggered acquisition overview B 2 typical acquisition figure B 2 programmable function inputs description B 1 overview 4 6 programming See application development PXI Star Trigger controller 4 7 PXI trigger bus overview 4 5 signal connection figure 4 8 specifications A 4 timebase signal 4 7 timing signals table 4 9 NI PXI 4224 User Manual Q questions and answers D 1 R regulatory compliance specifications A 6 removing NI PXI 4224 from Measurement amp Automation Explorer MAX C 2 from PXI chassis C 1 S safety specifications A 6 self calibration 5 12 self test verification measuring signal connections 3 1 voltage task or global channel 3 2 shielded ground referenced signal connection 2 12 signal conditi
58. on the PXI clock line These timebases are software configurable If you configure the device to use the internal timebase you can program the device to drive its internal timebase over the PXI trigger bus to another device programmed to receive this timebase signal This clock source whether local or from the PXI trigger bus is used directly by the device as the primary frequency source The default configuration is to use the internal timebase without driving the PXI trigger bus timebase signal The NI PXI 4224 can use the PXI_Trig lt 7 gt line to synchronize Master Timebase with other devices For the NI PXI 4224 PXI Trig lt 0 5 gt and PXI Star connect through the NI PXI 4224 backplane The PXI Star Trigger line allows the NI PXI 4224 to receive triggers from any Star Trigger controller plugged into slot 2 of the chassis For more information about the Star Trigger refer to the PXI Hardware Specification Revision 2 1 and PXI Software Specification Revision 2 1 National Instruments Corporation 4 7 NI PXI 4224 User Manual Chapter 4 Theory of Operation Figure 4 4 shows this signal connection scheme Z x DAQ STC 4 Y Al START TRIG 5 PXI Trigger lt 0 5 gt Al REF TRIG g 5 4 Al CONV CLK a A M gt AI SAMP CLK EIP DET 2 p AI PAUSE TRIG x I Al SAMPLE CLK TIMEBASE PXI Trigger lt 7 gt Switch 4 amp Master Timebase
59. onfigure your channels To create a LabVIEW property node complete the following steps 1 Launch LabVIEW 2 You can create the property node in a new VI or in an existing VI 3 Open the block diagram view 4 From the Functions toolbox select All Functions NI Measurements DAQmx Data Acquisition and select DAQmx Channel Property Node Left click inside the Property box and select Active Channels This allows you to specify exactly what channel s you want to configure If you want to configure several channels with different properties separate the lists of properties with another Active Channels box and assign the appropriate channel to each list of properties 3 Note If you do not use Active Channels the properties will be set on all of the channels in the task National Instruments Corporation Right click ActiveChan and select Add Element Left click the new ActiveChan Navigate through the menus and select the property you wish to define You must change the property to read or write to either get the property or write a new value Right click the property go to Change To and select Write Read or Default Value 5 7 NI PXI 4224 User Manual Chapter 5 Using the NI PXI 4224 8 Once you have added the property to the property node right click the terminal to change the attributes of the property or to add a control constant or indicator 9 To add another property to the property node right click
60. oning overview 4 3 signal connections analog input connections 2 3 floating signal source connection 2 11 ground referenced signal connection recommended 2 12 front signal connector 2 1 timing connections DAQ timing connections B 2 programmable function input connections B 1 signal measurement See measurement considerations SMB connector 2 1 PFI 0 CAL SMB connector 4 6 software installation 1 3 National Instruments ADE software 1 3 NI DAQ 1 3 version required D 1 ni com specifications analog input A 1 calibration A 3 CE compliance A 6 digital triggers A 3 electromagnetic compatibility A 6 environmental A 5 maximum working voltage A 5 memory A 3 overvoltage protection A 1 PCI bus interface A 4 physical A 4 power requirements A 4 PXI trigger bus A 4 regulatory compliance A 6 safety A 6 transfer characteristics A 2 Star Trigger controller 4 7 synchronization and triggering overview 5 8 program flow chart figure 5 9 using LabVIEW 5 10 T taking measurements See measurements theory of operation See also NI PXI 4224 block diagram of NI PXI 4224 4 2 timing and control overview 4 5 timing and triggering in application development 5 3 National Instruments Corporation Index timing connections DAQ timing connections typical posttriggered acquisition figure B 2 typical pretriggered acquisition figure B 2 overview B 1 programmable function inpu
61. ons In edge detection mode the minimum pulse width required is 10 ns This requirement applies for both rising edge and falling edge polarity settings There is no maximum pulse width requirement in edge detection mode In level detection mode there are no pulse width requirements imposed by the PFIs themselves Limits can be imposed by the particular timing signal being controlled These requirements are listed in the sections that describe the signals National Instruments Corporation B 1 NI PXI 4224 User Manual Appendix B Timing Signal Information DAQ Timing Connections The timing signals are AI START TRIG AI REF TRIG AI SAMP CLK AI CONV CLK AI PAUSE TRIG AI SAMPLE CLK TIMEBASE and AI HOLD COMPLETE Posttriggered DAQ allows you to view data that is acquired after a trigger event is received Figure B 1 shows a typical posttriggered sequence Al START TRIG Al SAMP CLK l 3 Al CONV CLK Waa Scan Counter 4 3 2 1 d Figure B 1 Typical Posttriggered Sequence Pretriggered DAQ allows you to view data that is acquired before the trigger of interest in addition to data acquired after the trigger Figure B 2 shows a typical pretriggered sequence eme i EO pi Ll nse IL TL TE TE SLL TIL noowe WICH Figure B 2 Typical Pretriggered S
62. or expressing a logarithmic measure of the ratio of two signal levels dB 20log V1 V2 for signals in volts Direct current An analog input consisting of two terminals both of which are isolated from computer ground the difference of which is measured Digital input output The addition of Gaussian noise to an analog input signal NI PXI 4224 User Manual Glossary DMA DNL driver E EEPROM EMC EMI ESD F FIFO floating signal sources G 8g gain gain accuracy NI PXI 4224 User Manual Direct memory access A method by which data can be transferred to from computer memory from to a device or memory on the bus while the processor does something else DMA is the fastest method of transferring data to from computer memory Differential nonlinearity A measure in least significant bit of the worst case deviation of code widths from their ideal value of 1 LSB Software that controls a specific hardware device such as a DAQ device Electrically erasable programmable read only memory ROM that can be erased with an electrical signal and reprogrammed Electromagnetic compatibility Electromagnetic interference Defines unwanted electromagnetic radiation from a device which could interfere with desired signals in test or communication equipment Electrostatic discharge First in first out memory buffer Signal sources with voltage signals that are not connected to an absolute refere
63. pin is selected as the source of AI START TRIG Refer to the AI REF TRIG Signal section for a complete description of the use of AI START TRIG and AI REF TRIG in a pretriggered operation Al REF TRIG Signal The AI REF TRIG signal can be input through PFI 0 PXI_Trig lt 0 5 gt or PXI Star Refer to Figure B 2 for the relationship of AI REF TRIG to the sequence As an input AI REF TRIG is configured in edge detection mode You can configure the polarity selection for either rising or falling edge The selected edge of AI REF TRIG initiates the posttriggered phase of a pretriggered sequence In pretriggered mode the AI START TRIG signal initiates the acquisition The scan counter SC indicates the minimum number of scans before AI REF TRIG is recognized After the SC decrements to zero it is loaded with the number of posttrigger scans to acquire while the acquisition continues The device ignores AI REF TRIG if itis asserted prior to the SC decrementing to zero After the selected edge of AI REF TRIG is received the device acquires a fixed number of scans and the acquisition stops In pretriggered mode the device acquires data both before and after receiving AI REF TRIG As an output AI REF TRIG reflects the posttrigger in a pretriggered sequence even if the acquisition is externally triggered by another PFI AI REF TRIG is not used in posttriggered DAQ The output is an active high pulse with a pulse width of 50 to 100 ns This output is
64. reserved Important Information Warranty The NI PXI 4224 is warranted against defects in materials and workmanship for a period of one year from the date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace equipment that proves to be defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the information in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National
65. rminal block Use Table 2 1 to make the signal connections if you are constructing a connector using a 25 pin D SUB connector Connect a timing or triggering signal to the PFI 0 CAL SMB connector using a cable with an SMB signal connector National Instruments Corporation 2 1 NI PXI 4224 User Manual Chapter 2 AN Connecting Signals Caution The PFI 0 CAL SMB connector is for low voltage timing and calibration signals only Voltages greater than 15 V can damage the device If you are building a 25 pin D SUB connector for your application make sure you use a connector and wires that are safety rated for the voltage and category of the signals in your application Table 2 1 NI PXI 4224 25 Pin D SUB Terminal Pin Assignments Front Connector Diagram Pin Number Signal Names Pin Number Signal Names 14 AIO 1 AIO 15 AII 2 AII 16 AI2 3 AI2 17 AI3 4 AI3 18 AIA4 5 AIA 19 AIS 6 AI5 20 AI6 7 AI6 N 21 AIT7 8 AI7 SN li 22 No Pin 9 No Pin Bo 23 NC 10 D GND t P 24 SPI CLK 11 MISO 25 SELECT 12 MOSI s N A N A 13 5 V NC No Connection NI PXI 4224 User Manual 2 2 ni com Chapter 2 Connecting Signals amp NATIONAL INSTRUMENTS NI PXI 4224 8 Chan Isgj amp tiog Amp ACCESS ACTIVE 3 a 0000000 o 9 Sc vo ES zz le Oc 6L Bt ZL O GL v ooo
66. st accurate Loading Calibration Constants Self Calibration NI PXI 4224 User Manual The NI PXI 4224 is factory calibrated before shipment at approximately 23 C to the levels indicated in Appendix A Specifications The associated calibration constants are stored in the onboard nonvolatile flash memory These constants are the values that were written to the CalDACs to achieve calibration in the factory and the remaining signal conditioning error The digitizer calibration constants are automatically read from the flash memory and loaded into the CalDACs by the NI PXI 4224 hardware the next time the device driver software is loaded The signal conditioning calibration constants are also read from the flash memory at this time The NI PXI 4224 can measure and correct for most of its offset errors without any external signal connections This calibration method is referred to as internal calibration or self calibration This internal calibration process which generally takes less than two minutes is the preferred method for assuring accuracy in your application Initiate an internal calibration to minimize the effects of any offset drifts particularly those due to changes in temperature To perform a self calibration complete the following steps 1 Double click the Measurement amp Automation Explorer icon on the desktop 2 Expand Devices and Interfaces to display the list of devices and interfaces 3 Expand NI DAQmx Devices to
67. st to determine which properties you need to set to configure the device for your application If you created the task and channels using the DAQ Assistant you can still modify the channel properties programmatically For a complete list of NI DAQmx properties refer to your ADE help file Table 5 1 NI DAQmx Properties Property Short Name Description Analog Input General Properties Input Configuration DC Allows NI DAQmx to measure the input signal AI Coupling Coupling Property GND Removes the signal source from the measurement and measures only ground Analog Input AI Gain Specifies the gain of the isolation amplifier General Properties Gain For the NI PXI 4224 you can specify 1 or 10 Analog Input General Properties Advanced High Accuracy Settings Auto Zero Mode AI AutoZeroMode Specifies when to measure ground NI DAQmx subtracts the measured ground voltage from every sample 3 Note Table 5 1 is a representative sample of important properties you can adjust in analog input measurements with the NI PXI 4224 It is not a complete list of NI DAQmx properties and does not include every property you may need to configure the device For a complete list of NI DAQmx properties and more information about NI DAQmx properties refer to your ADE help file NI PXI 4224 User Manual 5 4 ni com Chapter 5 Using the NI PXI 4224 Acquiring Analyzing and Present
68. t connections B 1 timing signal routing device and PXI clocks 4 7 programmable function inputs 4 6 B 1 timing signals See DAQ timing connections transfer characteristic specifications A 2 trigger bus See PXI trigger bus triggering See also synchronization and triggering digital trigger specifications A 3 hardware analog triggering D 1 troubleshooting common questions and answers D 1 V voltage maximum working voltage A 5 overvoltage protection A 1 voltage task creating 3 2 verifying 3 3 NI PXI 4224 User Manual
69. t panel user interface and a block diagram program Measured voltage Volts root mean square NI PXI 4224 User Manual Glossary W waveform Multiple voltage readings taken at a specific sampling rate working voltage The highest voltage with respect to ground that should be applied to an input terminal during normal use normally well under the breakdown voltage for safety margin Includes both the signal and common mode voltages NI PXI 4224 User Manual G 10 ni com Index A AI CONV CLK signal input signal timing figure B 7 output signal timing figure B 8 overview B 7 signal routing figure 4 6 AI HOLD COMPLETE signal description table 4 9 overview B 10 signal timing figure B 10 AI PAUSE TRIG signal description table 4 9 overview B 8 AI REF TRIG signal input signal timing figure B 4 output signal timing figure B 5 overview B 4 AI SAMP CLK signal input signal timing figure B 6 output signal timing figure B 6 overview B 5 AI SAMPLE CLK TIMEBASE signal description table 4 9 overview B 9 signal timing figure B 9 AI START TRIG signal description table 4 9 input signal timing figure B 3 output signal timing figure B 3 overview B 3 AI AutoZeroMode property table 5 4 AI Coupling property table 5 4 National Instruments Corporation analog input connections 2 3 ground referenced signal connection recommended figure 2 12 shielded 2 12 specific
70. to configure for input voltage range While making the selections you can select blocks of channels by pressing the lt Shift gt key or individual channels by pressing the Ctrl key Under the Settings tab set the input range by entering the Min and Max values Click the Device tab and select the Autozero mode 10 Repeat steps 7 through 9 until you have configured all the channels Note For more information about how to further configure the NI PXI 4224 or how to use LabVIEW to configure the device and take measurements refer to Chapter 4 Theory of Operation NI PXI 4224 User Manual 3 2 ni com Chapter 3 Configuring and Testing Verifying and Self Testing an NI DAQmx Task or Global Channel After you have created an analog input voltage NI DAQmx Task or NI DAQmx Global Channel verify the NI DAQmx Task or NI DAQmx Global Channel signal and functionality using the Test button in the toolbar Ifyou created an NI DAQmx Task set the timing and triggering settings you wish to use in the test in the Task Timing and Task Triggering tabs 2 Click the Test button to open the test panel and take a measurement You have now verified the NI PXI 4224 configuration and signal connection National Instruments Corporation 3 3 NI PXI 4224 User Manual Theory of Operation This chapter describes the theory of operation measurement considerations and timing information Theory of Operation Figure 4 1 illus
71. to high impedance at startup National Instruments Corporation B 5 NI PXI 4224 User Manual Appendix B Timing Signal Information NI PXI 4224 User Manual Figures B 7 and B 8 show the input and output timing requirements for AI SAMP CLK Rising Edge Polarity Falling Edge Polarity t 10 ns minimum Figure B 7 Al SAMP CLK Input Signal Timing d i gt Al SAMP CLK ty 50 to 100 ns a Start of Scan Start Pulse Al CONV REF n AI SAMP CLK 1 lt gt i tog 10 ns minimum 1 tot i b Scan in Progress Two Conversions per Scan Figure B 8 Al SAMP CLK Output Signal Timing The AI CONV CLK pulses are masked off until the device generates AI SAMP CLK If you use internally generated conversions the first AI CONV CLK appears when the onboard SI2 counter reaches zero If you select an external AI CONV CLK the first external pulse after B 6 ni com Appendix B Timing Signal Information AI SAMP CLK generates a conversion Separate the AI SAMP CLK pulses by at least one scan period A counter on the device internally generates AI SAMP CLK unless you select some external source The AI START TRIG signal starts this counter and the application software or the sample counter stops it Scans generated by either an internal or external AI SAMP CLK are inhibited unless they occur within a sequence Scans occurring within a sequen
72. to the Read Me First Safety and Radio Frequency Interference document shipped with the product for precautions to take When symbol is marked on a product it denotes a warning advising you to take precautions to avoid electrical shock When symbol is marked on a product it denotes a component that may be hot Touching this component may result in bodily injury Bold text denotes items that you must select or click in the software such as menu items and dialog box options Bold text also denotes parameter names Italic text denotes variables emphasis a cross reference hardware labels or an introduction to a key concept Italic text also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts Contents Chapter 1 About the NI PXI 4224 What You Need to Get Started AA 1 2 National Instruments Documentation eese ener nnne 1 3 Installing the Application Software NI DAQ and the DAQ Device 1 3 Installing the NI PX1 4224 esst 1 4 LED Pattern Descriptions e dern ertt rt er eee ore eae t Deed Ae 1 4 Chapter 2 Co
73. trates the key functional components of the NI PXI 4224 including the DAQ and integrated signal conditioning circuitry National Instruments Corporation 4 1 NI PXI 4224 User Manual Theory of Operation Chapter 4 UONe OS oido JO Nused uonelos dwy OSI oido e sod UOI ejos duy OSI Jet sod oido Uonelos dwy OSI oido e V isod A uonelos duy OSI oido Eug sod A UONe OS duy OSI oido Told sod Uonelos dwy OSI oido e sod UOI ejos duy OSI K IS1H nuo eoeyejul 1 eoepejul i i Ou E a sng sng ISL ef GE F A eb Addi n eoe di E a L 2 d fed eoegen Lei H 1 1 pue 3avova sng eng orsova i OO ee EE WB cate etd RPM i Jonuoo senbeg T v eoepeju Joquog 1 Jonuoo Buiur eoegejul x vna wo n gd WII
74. tudio and LabWindows CVI After you set up the hardware system use either your application software documentation or the NI DAQmx documentation to help you write your application If you have a large complicated system it is worthwhile to look through the software documentation before you configure the hardware Installing the Application Software NI DAQ and the DAQ Device Refer to the DAQ Getting Started Guide packaged with the NI DAQ software for instructions for installing your application software NI DAQ driver software and the DAQ device to which you will connect the NI PXI 4224 NI DAQ 7 3 1 or later is required to configure and program the NI PXI 4224 device If you do not have NI DAQ 7 3 1 or later you can either contact an NI sales representative to request it on a CD or download it from ni com National Instruments Corporation 1 8 NI PXI 4224 User Manual Chapter 1 About the NI PXI 4224 Installing the NI PXI 4224 ER Note Refer to the Read Me First Radio Frequency Interference document before removing equipment covers or connecting or disconnecting any signal wires Refer to the DAQ Getting Started Guide to unpack install and configure the NI PXI 4224 in a PXI chassis and then to the SCXI Quick Start Guide if you are using a PXI SCXI combination chassis LED Pattern Descriptions The following LEDs on the NI PXI 4224 front panel confirm the system is functioning properly e The ACCESS LED is
75. typically at high speeds in order to measure several signals with a single analog input channel G 6 ni com NI DAQmx noise normal mode voltage 0 OUT PCI PFI PGA port ppm PXI PXI trigger bus National Instruments Corporation G 7 Glossary The latest NI DAQ driver with new VIs functions and development tools for controlling measurement devices An undesirable electrical signal Noise comes from external sources such as the AC power line motors generators transformers fluorescent lights soldering irons CRT displays computers electrical storms welders radio transmitters and internal sources such as semiconductors resistors and capacitors Noise corrupts signals you are trying to send or receive Voltage that occurs in the case of interference between two conductors of a circuit Output pin A counter output pin where the counter can generate various TTL pulse waveforms Peripheral component interconnect Programmable function input Programmable gain amplifier 1 A communications connection on a computer or a remote controller 2 a digital port consisting of four or eight lines of digital input and or output Parts per million PCI eXtensions for Instrumentation An open specification that builds on the CompactPCI specification by adding instrumentation specific features The timing bus that connects PXI DAQ devices directly by means of connectors built into the backplane o
76. ultiplexer controlling the AI CONVERT CLOCK signal National Instruments Corporation 4 5 NI PXI 4224 User Manual Chapter 4 Theory of Operation PXI Trigger lt 0 5 gt m AI CONV CLK PXI Star gt PFI 0 gt Ctr 0 Internal Output gt Lose Figure 4 3 Al CONV CLK Signal Routing Figure 4 3 shows that AI CONV CLK can be generated from a number of sources such as the external signals PFI 0 PXI_Trig lt 0 5 gt and PXI Star and the Ctr 0 Internal Output Programmahle Function Inputs NI PXI 4224 User Manual PFI 0 is connected to the front SMB connector of the NI PXI 4224 Software can select PFI 0 as the external source for a given timing signal Any timing signal can use the PFI 0 pin as an input and multiple timing signals can simultaneously use the same PFI This flexible routing scheme reduces the need to change physical connections to the I O connector for different applications Refer to Table 4 2 for information regarding the available PFI 0 signals 4 6 ni com Chapter 4 Theory of Operation Device and PXI Clocks Many functions performed by the NI PXI 4224 require a frequency timebase to generate the necessary timing signals for controlling A D conversions digital to analog converter DAC updates or general purpose signals at the I O connector The NI PXI 4224 can use either its internal 20 MHz master timebase or a timebase received over the PXI trigger bus
77. unctions NI Measurements DAQmx Data Acquisition subpalette and accompanying subpalettes in LabVIEW Table 5 3 Synchronizing the NI PXI 4224 Using LabVIEW Flowchart Step VI or Program Step Create a Master Task optional DAQmx Create Task vi tThis VI is optional if you created and configured your task using the DAQ Assistant However if you use it in Lab VIEW any changes you make to the task will not be saved to a task in MAX Create Master AI Voltage Channels DAQmx Create Virtual Channel vi AI Voltage by default Configure Master Channels Use a DAQmx Channel Property Node Refer to the Using a DAQmx Channel Property Node in LabVIEW section for more information Configure Master Timing DAQmx Timing vi Sample Clock by default Get Master Timebase Source and Rate from Master Task Use a DAQmx Timing Property Node to get MasterTimebase Src and MasterTimebase Rate Create a Slave Task optional DAQmx CreateTask vi This Vlis optional if you created and configured your task using the DAQ Assistant However if you use it in LabVIEW any changes you make to the task will not be saved to a task in MAX Create Slave AI Voltage Channels DAQmx Create Virtual Channel vi AI Voltage by default Configure Slave Channels DAQmx Channel Property Node Refer to the Using a DAQmx Channel Property Node in LabVIEW section for more information Configure Slave Timin
78. xt Separate the AI CONV CLK pulses by at least one conversion period The NI PXI 4224 sample interval counter generates AI CONV CLK unless you select an external source The AI SAMP CLK signal starts the counter which counts down and reloads itself until the scan finishes The counter then reloads itself in preparation for the next AI SAMP CLK pulse A D conversions generated by an internal or external AI CONV CLK signal are inhibited unless they occur within a sequence Scans occurring within a sequence can be gated by either the hardware AI PAUSE TRIG signal or the software command register gate Al PAUSE TRIG Signal PFI 0 PXI_Trig lt 0 5 gt or PXI Star can externally input the AI PAUSE TRIG signal which is not available as an output on the I O connector AI PAUSE TRIG can mask off scans in a sequence You can configure the pin you select as the source for AI PAUSE TRIG in level detection mode You can configure the polarity selection for the pin as either active high or active low In level detection mode the AI SAMP CLK signal is masked off and no scans can occur AI PAUSE TRIG can neither stop a scan in progress nor continue a previously gated off scan In other words once a scan has started AI PAUSE TRIG does not gate off conversions until the beginning of the next scan Conversely if conversions are gated off AI PAUSE TRIG does not gate them back on until the beginning of the next scan B 8 ni com Appendix B Timi

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