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National Instruments NI 6614 User Manual

National Instruments NI 6614 User Manual

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NI 6614
User Manual
NI 6614 User Manual
August 2013
374038A-01

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Summary of Contents for National Instruments NI 6614

  • Page 1 NI 6614 User Manual NI 6614 User Manual August 2013 374038A-01...
  • Page 2 11500 North Mopac Expressway Austin, Texas 78759-3504 USA Tel: 512 683 0100 For further support information, refer to the Technical Support and Professional Services appendix. To comment on National Instruments documentation, refer to the National Instruments Web site at and enter the Info Code ni.com/info...
  • Page 3 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.
  • Page 4 ™ The ExpressCard word mark and logos are owned by PCMCIA and any use of such marks by National Instruments is under license. The mark LabWindows is used under a license from Microsoft Corporation. Windows is a registered trademark of Microsoft Corporation in the United States and other countries.
  • Page 5 Furthermore, any modifications to the product not expressly approved by National Instruments could void your authority to operate it under your local regulatory rules.

  • Page 6: Table Of Contents

    I/O Protection ......................2-15 DI Change Detection ....................2-16 DI Change Detection Applications..............2-17 Digital Filtering ......................2-17 Connecting Digital I/O Signals................. 2-19 Getting Started with DIO Applications in Software..........2-20 Signal Integrity Considerations ..................2-21 © National Instruments | vii...
  • Page 7 Contents Chapter 3 Counter Input Counter Overview......................3-1 Counter Input Applications....................3-2 Edge Counting ......................3-2 Channel Settings ....................3-2 Timing Settings....................3-3 Trigger Settings....................3-4 Other Settings ....................3-6 Exporting a Terminal Count Signal ..............3-6 Cascading Counters ..................3-6 Pulse Measurement ....................
  • Page 8 NI 6614 User Manual Chapter 4 Counter Output Counter Output Applications.................... 4-1 Generating a Series of One or More Pulses.............. 4-1 Create Channel ....................4-1 Channel Settings ....................4-2 Timing Settings....................4-2 Triggering Setting..................... 4-3 Generating a Waveform with Constant Frequency and Duty Cycle ......4-4 Create Channel ....................
  • Page 9 Contents Chapter 7 Clocks Clock Routing ........................7-1 100 MHz Timebase....................7-1 20 MHz Timebase..................... 7-1 100 kHz Timebase ....................7-2 External Reference Clock ..................7-2 10 MHz Reference Clock ..................7-2 PXIe_CLK100 ......................7-3 PXIe_SYNC100......................7-3 PXI_CLK10 ......................7-3 Synchronizing Multiple Devices ..................

  • Page 10: About This Manual

    About This Manual This manual describes the electrical and mechanical aspects of the National Instruments NI 6614 devices, and contains information about device operation and programming. Related Documentation The following documents contain information that you may find helpful as you read this manual: •...

  • Page 11: Introduction

    If you have not already installed the device, refer to the DAQ Getting Started documents. The NI 6614 is a timing and digital I/O device for use with PXIe chassis. The NI 6614 offers eight 32-bit counter channels and up to 32 lines of individually configurable, TTL/CMOS-compatible digital I/O.
  • Page 12 Chapter 1 Introduction Table 1-1 provides a list of accessories and cables available for use with NI 6614. Table 1-1. Accessories and Cables Accessory Description SH68-68-D1 Shielded 68-conductor cable R6868 cable Unshielded 68-conductor flat ribbon cable BNC-2121 BNC connector block with built-in test features...

  • Page 13: Digital I/O

    Digital I/O The NI 6614 contains 40 Programmable Function Interface (PFI) signals. These PFI signals can function as either timing input, timing output, or DIO signals. This chapter describes the DIO functionality. Refer to Chapter 6, PFI, for information on using the PFI lines as timing input or output signals.
  • Page 14 Table 2-2 lists the lines that do not populate CI. You must use the lines in Table 2-2 when measuring inputs frequencies above 25 MHz. For more information, refer to the NI 6614 Specifications.

  • Page 15: Digital Input Data Acquisition Methods

    NI 6614 User Manual Table 2-2. Lines without a populated CI Port 0 Port 1 PFI 11 / P0.11 PFI 35 / P1.3 PFI 15 / P0.15 PFI 39 / P1.7 PFI 19 / P0.19 — PFI 23 / P0.23 —...

  • Page 16: Digital Input Triggering

    Chapter 2 Digital I/O Hardware-timed operations can be buffered or hardware-timed single point. A buffer is a temporary storage in computer memory for to-be-transferred samples. • Buffered—Data is moved from the DAQ device’s onboard FIFO memory to a PC buffer using DMA before it is transferred to application memory.

  • Page 17: Digital Waveform Acquisition

    You can acquire digital waveforms on the Port 0 DIO lines. The DI waveform acquisition FIFO stores the digital samples. The NI 6614 has a DMA controller dedicated to moving data from the DI waveform acquisition FIFO to system memory. The device samples the DIO lines on each rising or falling edge of a clock signal, DI Sample Clock.

  • Page 18: Di Sample Clock Timebase Signal

    Chapter 2 Digital I/O If the NI 6614 receives a DI Sample Clock when the FIFO is full, it reports an overflow error to the host software. You can sample data on the rising or falling edge of DI Sample Clock.

  • Page 19: Di Start Trigger Signal

    NI 6614 User Manual The DI Sample Clock Timebase may be used if an external sample clock signal is required, but the signal needs to be divided down. If an external sample clock signal is required, but there is no need to divide the signal, then the DI Sample Clock should be used instead of the DI Sample Clock Timebase.

  • Page 20: Di Reference Trigger Signal

    Chapter 2 Digital I/O You also can specify whether the measurement acquisition begins on the rising- or falling-edge of DI Start Trigger. Routing DI Start Trigger to an Output Terminal You can route DI Start Trigger out to any PFI <0..39>, PXI_Trig <0..7>, or PXIe-DSTARC terminal.

  • Page 21: Di Pause Trigger Signal

    NI 6614 User Manual Using a Digital Source To use DI Reference Trigger with a digital source, specify a source and an edge. You can route many signals to DI Reference Trigger. To view the complete list of possible routes, see the Device Routes tab in MAX.

  • Page 22: Digital Output Data Generation Methods

    Chapter 2 Digital I/O Pause triggers are only sensitive to the level of the source, not the edge. Note Digital Output Data Generation Methods When performing a digital waveform operation, either software-timed or hardware-timed generations can be performed. Software-Timed Generations With a software-timed generation, software controls the rate at which data is generated.

  • Page 23: Digital Output Triggering

    Digital waveforms can be generated on the Port 0 DIO lines. The DO waveform generation FIFO stores the digital samples. NI 6614 has a DMA controller dedicated to moving data from the system memory to the DO waveform generation FIFO. The device moves samples from the FIFO to the DIO terminals on each rising- or falling-edge of a clock signal, DO Sample Clock.

  • Page 24: Do Sample Clock Signal

    Clock when the FIFO is empty, it reports an underflow error to the host software. By default, the NI 6614 routes the divided down DO Sample Clock Timebase to DO Sample Clock. You can route many other signals to DO Sample Clock. To view the complete list of possible routes, see the Device Routes tab in MAX.

  • Page 25: Do Sample Clock Timebase Signal

    The DO Sample Clock Timebase (do/SampleClockTimebase) signal is divided down to provide a source for DO Sample Clock. By default, the NI 6614 routes the onboard 100 MHz timebase to the DO Sample Clock Timebase. You can route many signals to DO Sample Clock Timebase.

  • Page 26: Do Pause Trigger Signal

    Chapter 2 Digital I/O The timing engine ignores the DO Start Trigger signal while the clock generation is in progress. After the clock generation is finished, the timing engine waits for another start trigger to begin another clock generation. Figure 2-9 shows a retriggerable DO of four samples. Figure 2-9.

  • Page 27: I/O Protection

    NI 6614 User Manual When using any signal other than the onboard clock as the source of your sample clock, the generation resumes as soon as the pause trigger is deasserted and another edge of the sample clock is received, as shown in Figure 2-11.

  • Page 28: Di Change Detection

    Chapter 2 Digital I/O DI Change Detection The device can be configured to detect changes in the DIO signals, which includes Port 0 and Port 1. Figure 2-12 shows a block diagram of the DIO change detection circuitry. Figure 2-12. DI Change Detection Enable P0.0 Synch...

  • Page 29: Di Change Detection Applications

    NI 6614 User Manual DI Change Detection Applications The DIO change detection circuitry can interrupt a user program when one of several DIO signals changes state. You also can use the output of the DIO change detection circuitry to trigger a DI or counter acquisition on the logical OR of several digital signals.
  • Page 30 Chapter 2 Digital I/O When multiple lines are configured with the same filter settings they are considered a bus. Two filtering modes for use with multiple lines: • Line filtering—Each line transitions independently of the other lines in the bus and acts like the behavior described above •...

  • Page 31: Connecting Digital I/O Signals

    NI 6614 User Manual • Case 2—If an additional line on the bus also has a transition during the filter clock period, the change is not propagated until the next filter clock edge, as shown in Figure 2-15. Figure 2-15. Case 2...

  • Page 32: Getting Started With Dio Applications In Software

    Exceeding the maximum input voltage ratings, which are listed in the Caution specifications document for each NI 6614 device, can damage the device and the computer. NI is not liable for any damage resulting from such signal connections. Getting Started with DIO Applications in Software The NI 6614 can be used in the following digital I/O applications: •...

  • Page 33: Signal Integrity Considerations

    NI 6614 User Manual To locate LabVIEW, LabWindows/CVI, Measurement Studio, Visual Basic, and ANSI C examples, refer to the KnowledgeBase document, Where Can I Find NI-DAQmx Examples?, by going to and entering the Info Code ni.com/info daqmxexp For additional examples, refer to zone.ni.com...

  • Page 34: Counter Input

    Counter Input Counter Overview The NI 6614 has eight general-purpose 32-bit counter/timers and a frequency generator. The general-purpose counter/timers can be used for many measurement and pulse generation applications. Figure 3-1 shows Counter 0 and the frequency generator. All eight counters are identical.

  • Page 35: Counter Input Applications

    Chapter 3 Counter Input For measurements using a sample clock, you must configure the NI 6614 to route a signal to the sample clock input of the counter. The NI 6614 does not have a dedicated circuit to generate a counter sample clock.

  • Page 36: Timing Settings

    NI 6614 User Manual You can change these behaviors by configuring DAQmx Channel properties: • CI.CountEdges.InitialCnt—To specify the initial value of the count. • CI.CountEdges.Term—The signal-to-measure comes from an input terminal. To change the signal-to-measure, specify a different terminal via this property.

  • Page 37: Trigger Settings

    Chapter 3 Counter Input On each sample clock, the device stores the current count value in a buffer. Use DAQmx Read to read the values from this buffer. Figure 3-4 shows an example using Sample Clock Timing. Figure 3-4. Edge Counting: Sample Clock Timing Start Task Signal to Measure Count...
  • Page 38 NI 6614 User Manual Using a Pause Trigger To configure the counter to pause counting based on a hardware signal, use a Pause Trigger. Set Pause.TrigType to Digital Level. Set Pause.DigLvl.Src to select what signal to use as the Pause Trigger.

  • Page 39: Other Settings

    Chapter 3 Counter Input Other Settings You can filter noise on any PFI signal that is an input to the counter by enabling a filter. Refer to the PFI Filters section in Chapter 6, PFI, for more information. If you route the same PFI signal to multiple destinations, you should enable the Synchronization feature.

  • Page 40: Create Channel

    NI 6614 User Manual Figure 3-8. Pulse Measurement DAQmx DAQmx Start Task Read Read Pulse Pulse Pulse High Pulse Low High Signal to Measure Counter Timebase Count Buffer Read Value Create Channel To make a Pulse measurement, first create a virtual channel. Use one of following three VIs or functions depending on the type of data you want DAQmx to return: •...

  • Page 41: Timing Settings

    Chapter 3 Counter Input • To specify on which edge, rising or falling, to begin the measurement, select the appropriate property from the following list that corresponds to the type of channel created, and then set this property to rising or falling. •...

  • Page 42: Trigger Settings

    NI 6614 User Manual Sample Clock With Sample Clock timing, on each active edge of the sample clock, the device stores one measurement. The one measurement is the high and low pulse times of the most recent full pulse to occur before the sample clock. Figure 3-10 shows an example using Sample Clock timing.

  • Page 43: Other Settings

    Chapter 3 Counter Input Other Settings The counter measures the pulse using the Counter Timebase signal. By default, the counter uses an onboard 100 MHz signals as the timebase. To change the timebase, use the CI.CtrTimebaseSrc DAQmx Channel property. You can filter noise on any PFI signal that is an input to the counter by enabling a filter. Refer to the PFI Filters section in Chapter 6, PFI, for more information.

  • Page 44: Settings

    CI.SemiPeriod.Term to change the signal-to-measure. Pulse measurements support sample clock timing; Semi-Period measurements do not. Frequency Measurement Frequency Measurement Considerations The NI 6614 supports five methods for measuring frequency. Table 3-1 summarizes the five frequency measurement methods. Table 3-1. Frequency Measurement Methods Number...
  • Page 45 • Number of Counters Some methods use two of the eight counters on the NI 6614; other methods use one of the eight counters. 3-12 | ni.com...

  • Page 46: Frequency Measurement Methods

    NI 6614 User Manual Frequency Measurement Methods This section describes the frequency measurement methods supported by the NI 6614. Sample Clock (with Averaging) With this method, for each sample clock the counter counts the number of full periods (T1) of the signal-to-measure since the previous sample clock.
  • Page 47 Chapter 3 Counter Input To use the Sample Clock (with Averaging) method, configure the following: • DAQmx Create channel (CI-Frequency)—Use this VI or function to create the channel. • DAQmx Timing (Sample Clock)—Use this VI or function to set the number of samples, sample clock source, and other properties.
  • Page 48 NI 6614 User Manual • CI.Freq.EnableAveraging—Set this property to False. By default, the counter measures the frequency on a default PFI terminal (refer to Chapter 5, Counter Signal Routing, for more information) and use an onboard 100 MHz clock as the timebase.
  • Page 49 Chapter 3 Counter Input By default, the counter measures the frequency on a default PFI terminal (refer to Chapter 5, Counter Signal Routing, for more information) and use an onboard 100 MHz clock as the timebase. To change the signals used for this measurement, configure the following: •...
  • Page 50 NI 6614 User Manual With N as the integer that divides down the input signal (f ), which can be configured in CI.Freq.Div, the maximum error and maximum frequency error for this method are given by: × Maximum Error (%)
  • Page 51 Chapter 3 Counter Input Figure 3-19. Frequency Measurement: High Frequency with Two Counters Counter Pulse Source Timebase (f ) k Counter M Source Counter N Signal to Gate Measure Pulse … Signal to Measure (f ) With the known measurement time (T ), which can be configured in CI.Freq.MeasTime, the maximum error and maximum frequency error for this method are given by: ×...

  • Page 52: Period Measurement

    NI 6614 User Manual By default, the counters measure the frequency on a default PFI terminal (refer to Chapter 5, Counter Signal Routing, for more information) and use an onboard 100 MHz clock as the timebase. To change the signals used for this measurement, configure the following: •...

  • Page 53: Channel Settings

    Chapter 3 Counter Input Channel Settings By default, the counter: • measures pulses on a default PFI terminal. Refer to Chapter 5, Counter Signal Routing, for more information. • measures a high pulse. That is, the counter begins measuring the time from a rising edge to the next falling edge.

  • Page 54: Trigger Settings

    NI 6614 User Manual Figure 3-21. Pulse-Width Measurement: Implicit Timing DAQmx Start Task Arm Start Trigger Signal to Measure Counter Timebase Counter Value Buffer To use Implicit timing, use the DAQmx Timing (Implicit) VI or function. Sample Clock With Sample Clock timing, on each active edge of the sample clock, the device stores one measurement.

  • Page 55: Other Settings

    Chapter 3 Counter Input Figure 3-23 shows an example of a Pulse-Width measurement using an Arm Start Trigger. Note that if the counter is armed while the signal-to-measure is already in the active state, the counter will wait to perform the measurement on the next full pulse after the Arm Start Trigger. Figure 3-23.

  • Page 56: Channel Settings

    NI 6614 User Manual Channel Settings By default, the counter: • monitors for events on default PFI terminals. Refer to Chapter 5, Counter Signal Routing, for more information. • looks for rising edges on the first signal and second signal.

  • Page 57: Trigger Settings

    Chapter 3 Counter Input Implicit Timing With Implicit timing, the device measures the time between every pair of beginning and ending events. The measurements are stored in a buffer. Each call to DAQmx Read returns values from this buffer. Figure 3-25 shows an example of Implicit timing. Figure 3-25.

  • Page 58: Other Settings

    If you route the same PFI signal to multiple destinations, you should enable the Synchronization feature. Refer to Chapter 6, PFI, for more information. Quadrature and Two-Pulse Encoder Overview The NI 6614 can make angular and linear position measurements using quadrature and two-pulse encoders. Quadrature Encoders A quadrature encoder can have up to three channels: channels A, B, and Z.

  • Page 59: Two-Pulse Encoders

    Chapter 3 Counter Input • X4 Encoding—The counter increments or decrements on each edge of channels A and B. Whether the counter increments or decrements depends on which channel leads the other. Each cycle results in four increments or decrements, as shown in Figure 3-29. Figure 3-29.

  • Page 60: Angular Position Measurement

    NI 6614 User Manual Figure 3-31. Measurements Using Two Pulse Encoders Ch A Ch B Counter Value 2 Angular Position Measurement In an angular measurement task, the counter measures the angle of a quadrature encoder or two-pulse encoder. Refer to the...

  • Page 61: Timing Settings

    By default, the counter uses On-Demand (no sample clock) timing. The counter starts counting when software calls DAQmx Start Task. Each time software calls DAQmx Read, the NI 6614 returns the current angle of the encoder. Figure 3-32 shows an example of On-Demand timing.

  • Page 62: Trigger Settings

    NI 6614 User Manual Trigger Settings By default, the counter begins counting when you call DAQmx Start Task. To have the counter begin counting in response to a hardware trigger, use an Arm Start Trigger. Set ArmStart.TrigType to Digital Edge.

  • Page 63: Counter Output

    Complex waveform or timing pattern Generating a Series of One or More Pulses The NI 6614 can generate a series of one or more pulses, where each pulse is the same duration. Create Channel You specify the characteristics of the pulses when you create the channel. You can specify the pulses in terms of time, ticks of the timebase clock, or in terms of frequency and duty cycle.

  • Page 64: Channel Settings

    Chapter 4 Counter Output Time To specify the pulses in terms of time, use the DAQmx Create Channel (CO Pulse-Generation Time) VI or function. Figure 4-2 shows how to specify the pulses in terms of time. Figure 4-2. Specifying Pulses Start Task Idle State = Low High...

  • Page 65: Triggering Setting

    NI 6614 User Manual Triggering Setting By default, the NI 6614 begins generating the pulses when you call the DAQmx Start Task VI or function. The NI 6614 can also begin generating pulses in response to a digital trigger. Figure 4-3 shows an example using a digital trigger.

  • Page 66: Generating A Waveform With Constant Frequency And Duty Cycle

    By default, the NI 6614 begins generating the waveform when the DAQmx Start Task VI or function is called. The NI 6614 can also begin generating pulses in response to a digital trigger. Figure 4-6 shows an example where pulses are generated in response to a digital trigger.

  • Page 67: Generating A Waveform With Variable Frequency And Duty Cycle

    The counter begins by generating a waveform with an initial frequency and duty cycle. On the first active edge of sample clock, the NI 6614 reads the first sample out of the buffer. The first sample consists of two values: frequency1 and duty_cycle1. The counter begins generating a waveform with frequency1 and duty_cycle1.

  • Page 68: Create Channel

    Clock) VI or function. Triggering Settings By default, the NI 6614 begins generating the pulses when you call the DAQmx Start Task VI or function. The NI 6614 can also begin generating pulses in response to a digital trigger. To use a start trigger, call the DAQmx Start Trigger (Digital Edge) VI or function. Inputs to this VI or function include: •...

  • Page 69: Buffer Considerations

    Start.Delay, Start.DelayUnits—Specifies the delay from when the trigger occurs to when the NI 6614 begins generating pulses. Even if the Start.Delay is set to 0, the NI 6614 inserts a minimum delay equal Note to two ticks of the counter timebase.

  • Page 70: Create Channel

    Triggering Setting By default, the NI 6614 begins generating the pulses when you call the DAQmx Start Task VI or function. The NI 6614 can also begin generating pulses in response to a digital trigger. To use a start trigger, call the DAQmx Start Trigger (Digital Edge) VI or function. Inputs to this VI or function include: •...

  • Page 71: Buffer Considerations

    Frequency Division The counters can generate a signal with a frequency that is a fraction of an input signal. With frequency division, the NI 6614 receives a signal with frequency, f, and outputs a signal with frequency, f/N. For frequency division, use the steps described in...
  • Page 72 Chapter 4 Counter Output The Frequency Generator can use one of three timebases: 20 MHz, 10 MHz or 100 kHz. The timebase can be divided by any integer from 1 to 16 to create the FREQ OUT signal. Create a virtual channel using the DAQmx Create Channel (CO-Pulse Generation-Frequency) VI or function.

  • Page 73: Counter Signal Routing

    Counter Signal Routing NI 6614 has flexible signal routing features. Signals can be routed to or from: • PFI terminals on the front panel I/O connector • any of the eight counters • the Digital I/O circuits • other devices in your PXI chassis using backplane PXI signals such as PXI_TRIG<7..0>...
  • Page 74 Table 5-1. Default Routing for Counter Input Signals Measurement Ctr0 Ctr1 Ctr2 Ctr3 Ctr4 Ctr5 Ctr6 Ctr7 Count Edges Edges PFI 39 PFI 35 PFI 31 PFI 27 PFI 23 PFI 19 PFI 15 PFI 11 Count Direction PFI 37 PFI 33 PFI 29 PFI 25...

  • Page 75: Routing Options

    Input, for more information about changing the signal routed to each counter. To view a complete list of possible routes for each signal, use the Device Routes table for NI 6614 in Measurement & Automation Explorer (MAX). To view this table: Launch Measurement & Automation Explorer (MAX) by navigating to Start»All Programs»National Instruments»Measurement &...
  • Page 76 Chapter 5 Counter Signal Routing Table 5-3. Matching Routing Terminology DAQmx Property Counter Input Signal ArmStart.DigEdge.Src CtrnArmStartTrigger CI.CountEdges.CountReset.Term CtrnGate CI.CountEdges.DirTerm CtrnB CI.CountEdges.Term CtrnSource CI.Encoder.AInputTerm CtrnA CI.Encoder.BInputTerm CtrnB CI.Encoder.ZInputTerm CtrnZ CI.Freq.Term Low Frequency with One Counter or CtrnGate when using Sample Clock Large Range with Two Counter or CtrnSource High Frequency with Two Counters...

  • Page 77: Pfi

    NI 6614 devices have up to 40 Programmable Function Interface (PFI) signals. Each PFI can be individually configured as the following: • A static digital input • A static digital output • A timing input signal for DI, DO, or counter/timer functions •...

  • Page 78: Using Pfi Terminals As Timing Input Signals

    Chapter 6 Using PFI Terminals as Timing Input Signals Use PFI terminals to route external timing signals to many different functions. Each PFI terminal can be routed to any of the following signals: • Counter input signals for all counters—Source, Gate, Aux, HW_Arm, A, B, Z •...

  • Page 79: Using Pfi Terminals As Static Digital I/Os

    NI 6614 User Manual Using PFI Terminals as Static Digital I/Os Each PFI can be individually configured as a static digital input or a static digital output. When a terminal is used as a static digital input or output, it is called P0.x or P1.x. On the I/O connector, each terminal is labeled PFI x/P0.x or PFI x/P1.x.
  • Page 80 Chapter 6 The following is an example of low to high transitions of the input signal. High-to-low transitions work similarly. Assume that an input terminal has been low for a long time. The input terminal then changes from low to high, but glitches several times. When the filter clock has sampled the signal high on N consecutive edges, the low to high transition is propagated to the rest of the circuit.

  • Page 81: I/O Protection

    75 Ω. When connecting signals to the NI 6614, this impedance needs to be matched as closely as possible. When driving signals into the NI 6614, use a driver with 75 Ω output impedance as shown in Figure 6-4.
  • Page 82 Pin 2 Pin 36 The NI 6614 has 40 PFI pins. Each PFI pin is paired with a particular GND pin. The SH68-68-D1 cable twists each PFI pin with its corresponding GND pin. Table 6-2 shows the corresponding GND pin for each PFI pin. If you are using a 68-pin screw terminal accessory or designing your own accessory, make sure to connect your GND signal to the appropriate GND pin as shown in this table.
  • Page 83 NI 6614 User Manual Table 6-2. Signals and D GND Pin Number on 68-Pin Screw Terminal Accessory (Continued) PFI/DIO Number Pin Number for D GND PFI 14 / P0.14 PFI 15 / P0.15 PFI 16 / P0.16 PFI 17 / P0.17 PFI 18 / P0.18...

  • Page 84: Clock Routing

    Clocks This chapter describes the clock system of the NI 6614. Clock Routing Figure 7-1 shows the clock routing circuitry of an NI 6614 device. Figure 7-1. Clock Routing Circuitry Onboard 10 MHz RefClk (To PXI_Trigger <0..7> 10 MHz & PFI <0..39>...

  • Page 85: 100 Khz Timebase

    10 MHz Reference Clock The 10 MHz reference clock can be used to synchronize other devices to your NI 6614 device. The 10 MHz reference clock can be routed to the PXI_Trigger <0..7> or PFI <0..39> terminals.

  • Page 86: Pxie_Clk100

    Timebase accuracy translates directly to measurement and pulse generation accuracy. The onboard OCXO can also overdrive the PXI(e) backplane clocks, allowing all modules locked to a PXI(e) backplane clock to obtain the NI 6614 OCXO accuracy and stability.

  • Page 87: Using The Ocxo To Overdrive The Pxi Backplane Clock

    PXI system when using a PXI backplane clock as the reference clock source. The NI 6614 automatically drives the 10 MHz OCXO clock onto the chassis PXI_Clk10_In when installed into the chassis system timing slot. In most chassis driving PXI_Clk10_In automatically overrides the chassis built in oscillator.
  • Page 88 Figure 7-2. Using the OCXO to Overdrive the Chassis Backplane Clock PXIe Chassis Rear 10 MHz Panel Oscillator 10 MHz Ref In NI 6614 in the System Timing Slot Other External Onboard Ref Clk 10 MHz OCXO Buffer & PLL...

  • Page 89: Pxi Triggers

    In a PXI chassis with more than eight slots, PXI trigger lines may be divided into multiple independent buses. PXI_Trigger<0..7> are bidirectional signals. PXI_STAR The NI 6614 device receives the PXI_STAR signal from a Star Trigger controller in a different slot of the PXI Chassis. Refer to the PXI Express Specification at for more www.pxisa.org information.
  • Page 90 Chapter 8 PXI Triggers Table 8-1 describes the three differential star (DSTAR) lines and how they are used. Table 8-1. PXIe-DSTAR Line Descriptions Trigger Line Purpose PXIe_DSTARA Distributes high-speed, high-quality clock signals from the system timing slot to the peripherals (input). PXIe_DSTARB Distributes high-speed, high-quality trigger signals from the system timing slot to the peripherals (input).

  • Page 91: Bus Interface

    Bus Interface The bus interface circuitry of NI 6614 efficiently moves data between host memory and the measurement and acquisition circuits. Data Transfer Methods Refer to the following sections for information about bus interface data transfer methods for devices. PXI Express Device Data Transfer Methods The primary ways to transfer data across the PXI Express bus are as follows: •...

  • Page 92: Pxi Express Considerations

    Chapter 9 Bus Interface Each DMA controller supports several features to optimize PXI Express bus utilization. The DMA controllers pack and unpack data through the FIFOs. The DMA controllers also automatically handle unaligned memory buffers on PXI Express. • Programmed I/O—Programmed I/O is a data transfer mechanism where the user’s program is responsible for transferring data.

  • Page 93: Calibration

    OCXO. National Instruments recommends that you calibrate the NI PXIe-6614 yearly. In order to calibrate and adjust your device to correct the drift in frequency, refer to the NI 6614 Calibration Procedure for more information. © National Instruments | 10-1...

  • Page 94: Pinout And Signal Descriptions

    Pinout and Signal Descriptions Figure A-1 shows the NI PXIe-6614 pinout. The descriptions beside each pin are in the following format: Signal Name / DIO Context / Counter Context (Default). © National Instruments | A-1...
  • Page 95 Appendix A Pinout and Signal Descriptions 6614 Pinout Figure A-1. NI PXIe- 34 68 PFI 31/P0.31/CTR 2 SOURCE D GND 33 67 D GND PFI 30/P0.30/CTR 2 GATE 32 66 PFI 28/P0.28/CTR 2 OUT PFI 29/P0.29/CTR 2 AUX 31 65 PFI 27/P0.27/CTR 3 SOURCE D GND 30 64...
  • Page 96 You can also register for instructor-led, hands-on courses at locations around the world. • System Integration—If you have time constraints, limited in-house technical resources, or other project challenges, National Instruments Alliance Partner members can help. To learn more, call your local NI office or visit ni.com/alliance •...
  • Page 97 Appendix B Technical Support and Professional Services You also can visit the Worldwide Offices section of to access the branch ni.com/niglobal office Web sites, which provide up-to-date contact information, support phone numbers, email addresses, and current events. B-2 | ni.com...

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