background image

Figure 4.

 on page 15 and 

Figure 5.

 on page 16 summarize the routing features of the

PXIe-6674. The remainder of this chapter details the capabilities and constraints of the routing
architecture.

Figure 4. High-Level Schematic of PXIe-6674 Signal Routing Architecture

÷2

N

÷2

M

÷2

N

÷2

M

Selection

Circuitry

PXI_STAR 0

PXI_STAR 1

PXI_STAR 16

Selection

Circuitry

Selection

Circuitry

Selection

Circuitry

PXI_TRIG 0

PXI_TRIG 1

PXI_TRIG 7

Selection

Circuitry

Selection

Circuitry

Selection

Circuitry

Selection

Circuitry

Selection

Circuitry

3

SYNCHRONIZATION

CLOCKS for PFI<0..5>

and PFI_LVDS<0..2>

53

SOURCE

*

3

*

PXI_STAR<0..16>, PXI_TRIG<0..7>,
PFI<0..5>, PFI_LVDS<0..2>,
PXIe_DSTARC<0..16>, Steady
Logic, and Software Trigger are
routed to SOURCE of each Selection
Circuitry block.

SYNCHRONIZATION CLOCKS

for PXI_STAR<0..16>, PXI_TRIG<0..7>,

and PXIe-DSTARB<0..16>

Selection

Circuitry

Selection

Circuitry

Selection

Circuitry

PFI 0

PFI 1

PFI 2

PFI 3

PFI 4

PFI 5

PFI_LVDS 0

PFI_LVDS 1

PFI_LVDS 2

Selection

Circuitry

PXIe_DSTARB 0

PXIe_DSTARB 1

PXIe_DSTARB 16

Selection

Circuitry

Selection

Circuitry

CLKIN
OCXO

Clock Generation

PXIe-CLK100

PXI_CLK10

CLKIN
OCXO

Clock Generation

PXIe-CLK100

PXI_CLK10

Selection

Circuitry

Selection

Circuitry

Selection

Circuitry

Figure 5.

 on page 16 provides a more detailed view of the selection circuitry referenced in 

Figure 4.

 on page 15.

PXIe-6674 User Manual

  | 

© National Instruments

  | 

15

Summary of Contents for PXIe-6674

Page 1: ...tware Use the documentation you have as follows Measurement hardware documentation This documentation contains detailed information about the measurement hardware that plugs into or is connected to the computer Use this documentation for hardware installation and configuration instructions specifications about the measurement hardware and application hints Software documentation Refer to the NI Sy...

Page 2: ...you to share clocks and triggers between modules in a PXI Express chassis and other PXI chassis or non PXI systems This is done without using the system timing slot in your PXI Express chassis The PXIe 6674 module generates and routes clock signals between devices in multiples chassis providing a method for synchronizing multiple devices in a PXI Express system What You Need to Get Started To set ...

Page 3: ...EW Data Acquisition VI Library a series of virtual instruments for using LabVIEW with National Instruments DAQ hardware is included with LabVIEW LabWindows CVI is a complete ANSI C ADE that features an interactive user interface code generation tools and the LabWindows CVI Data Acquisition and Easy I O libraries Safety Information The following section contains important safety information that yo...

Page 4: ...stand voltage levels that commonly occur in electrical distribution systems The following is a description of measurement categories Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS voltage This category is for measurements of voltages from specially protected secondary circuits Such voltage measureme...

Page 5: ...press chassis The PXIe 6674 can be placed in any PXI Express slot as indicated by the glyph in Figure 1 on page 5 Figure 1 PXI Express Slot Indicator Glyph 3 Remove the filler panel for the selected slot if applicable 4 Ground yourself using a grounding strap or by touching a grounded object Follow the ESD protection precautions described in the Unpacking section of the Introduction 5 Carefully in...

Page 6: ... on the front panel provide information about module status The front panel descriptions in the Hardware Overview describe the LEDs in greater detail Hardware Overview This chapter presents an overview of the hardware functions of the PXIe 6674 Figure 2 on page 7 provides a functional overview of the PXIe 6674 hardware 6 ni com PXIe 6674 User Manual ...

Page 7: ...LK100 PXIe_DSTARB Peripheral PXIe_DSTARC Peripheral PFI 0 Threshold DAC PFI 0 Driver Comparator Driver Comparator PFI 1 Threshold DAC LVDS Driver Receiver PFI 1 PFI 2 Threshold DAC PFI 2 Driver Comparator Driver Comparator PFI 3 Threshold DAC LVDS Driver Receiver PFI 3 PFI 4 Threshold DAC PFI 4 Driver Comparator Driver Comparator PFI 5 Threshold DAC LVDS Driver Receiver PFI 5 PFI_LVDS 0 2 PFI 0 5 ...

Page 8: ...el 1 2 3 5 4 Timing Module NI PXIe 6674 PFI 0 LVDS 0 PFI 1 LVDS 0 PFI 2 LVDS 1 PFI 3 LVDS 1 PFI 5 LVDS 2 PFI 4 LVDS 2 CLK OUT CLK IN 1 Access LED 2 Active LED 3 CLKOUT Connector 4 PFI 0 5 PFI_LVDS 0 2 Connectors 5 CLKIN Connector 8 ni com PXIe 6674 User Manual ...

Page 9: ...has initiated the module Amber Module is being accessed The Access LED flashes amber for 50 ms when the module is accessed Blinking Red Module has detected an over temperature condition Solid Red A hardware error has been detected Caution If the Access LED is observed to be blinking red the module has detected an over temperature condition Continued use of the PXIe 6674 in this condition is not re...

Page 10: ...n Description PXI_CLK10 In from chassis This signal is the PXI 10 MHz backplane clock This signal is the output of the native 100 MHz oscillator in the chassis divided by ten PXIe_CLK100 In from chassis This signal is the PXI Express 100 MHz backplane clock PXIe CLK100 offers tighter slot to slot timing than PXI_CLK10 CLKIN In from front panel CLKIN is the signal connected to the SMA input connect...

Page 11: ...GA PXI_TRIG 0 7 In Out to from chassis The PXI trigger bus consists of eight digital lines shared among all slots in the PXI Express chassis The PXIe 6674 can route a wide variety of signals to and from these lines Note PXI_TRIG 0 5 are also known as RTSI 0 5 in some hardware devices and APIs However PXI_TRIG 6 7 are not identical to RTSI 6 7 PXI_STAR In Out to from chassis The PXI star trigger bu...

Page 12: ...4 for routing clock signals Clock Generation The PXIe 6674 includes built in advanced clock generation circuitry for generating clock signals below 1 Hz to 1 GHz with very fine frequency resolution The clock generation circuitry is based on a direct digital synthesis DDS with an 800 MHz reference phase locked to PXIe_CLK100 This allows the DDS to generate a 150 MHz to 300 MHz signal with microhert...

Page 13: ...n a star configuration PXIe_DSTARA uses LVPECL signaling and closely matched trace lengths to achieve low skew high speed clock routing capabilities The PXIe 6674 can route its DSTARA to CLKOUT and PFI_LVDS PXIe_DSTARB PXIe_DSTARB is used to send trigger signals from the system timing slot to each PXI Express peripheral slot in a star configuration PXIe_DSTARB uses LVDS signaling and closely match...

Page 14: ... LVDS Triggers section for details on using PFI_LVDS for sending and receiving trigger signals CLKOUT The CLKOUT SMA connector on the front panel provides a means to export a clock signal from the PXIe 6674 to an external device or another system timing module The CLKOUT driver uses two separate circuits for driving CLKOUT one for low speed frequencies 50 MHz and below and one for high speed above...

Page 15: ...RCE 3 PXI_STAR 0 16 PXI_TRIG 0 7 PFI 0 5 PFI_LVDS 0 2 PXIe_DSTARC 0 16 Steady Logic and Software Trigger are routed to SOURCE of each Selection Circuitry block SYNCHRONIZATION CLOCKS for PXI_STAR 0 16 PXI_TRIG 0 7 and PXIe DSTARB 0 16 Selection Circuitry Selection Circuitry Selection Circuitry PFI 0 PFI 1 PFI 2 PFI 3 PFI 4 PFI 5 PFI_LVDS 0 PFI_LVDS 1 PFI_LVDS 2 Selection Circuitry PXIe_DSTARB 0 PX...

Page 16: ...ignal routing operations can be characterized by a source input and a destination In addition synchronous routing operations must also define a third signal known as the synchronization clock Refer to the Choosing the Type of Routing section for more information on synchronous routing versus asynchronous routing Figure 6 on page 17 summarizes the sources and destinations of the PXIe 6674 16 ni com...

Page 17: ...nce and minimize reflections Note Terminating the signals with a 50 Ω resistance is recommended when the source is another PXIe 6674 or any other source with a 50 Ω output The voltage thresholds for the front panel PFI inputs are programmable The input signal is generated by comparing the input voltage on the PFI connectors to the voltage output of software programmable DACs The thresholds for the...

Page 18: ...s You can independently select the output signal source for each of the PFI lines from one of the following sources Another PFI 0 5 Another PFI pair in LVDS mode PXI_TRIG 0 7 PXI_STAR Global software trigger PFI synchronization clock PXIe_DSTARB Steady logic high or low The PFI synchronization clock may be any of the following signals Clock Generation PXI_CLK10 PXIe_CLK100 CLKIN Any of the previou...

Page 19: ...XI_CLK10 PXIe_CLK100 CLKIN Any of the previously listed signals divided by the first frequency divider 2n up to 512 Any of the previously listed signals divided by the second frequency divider 2m up to 512 Refer to the Choosing the Type of Routing section for more information on the synchronization clock Note The PFI synchronization clock is the same for all routing operations in which PFI 0 5 or ...

Page 20: ... Type of Routing section for more information about the synchronization clock Note The backplane synchronization clock is the same for all routing operations in which PXI_TRIG 0 7 PXIe_DSTARC or PXI_STAR is defined as the output although the divide down ratio for this clock full rate first divider second divider may be chosen on a per route basis Using the PXI Star Trigger There are up to 17 PXI s...

Page 21: ...eripheral modules using PXIe_DSTARB Both PXIe_DSTARB and PXIe_DSTARC are one directional The PXI Express Specification requires PXI Express chassis to limit the skew between any two PXIe_DSTAR routes to 150 ps The PXIe 6674 receives PXIe_DSTARB and can route it as a trigger source The PXIe 6674 can independently select from the following sources to be routed to PXIe_DSTARC PFI 0 5 PFI_LVDS 0 2 PXI...

Page 22: ... source Propagation delay of the signal across the backplane s and cable s Propagation delay of the signal through the PXIe 6674 Time for the receiver to recognize the signal Both the source and the destination of an asynchronous routing operation on the PXIe 6674 can be any of the following lines Any front panel PFI pin PFI 0 5 as single ended Any front panel PFI pin as LVDS PFI_LVDS 0 2 Any PXI ...

Page 23: ...owever if the trigger is sent and received synchronously using a low skew synchronization clock for example PXI_CLK10 all receiving devices can act on the trigger at the same time as shown in Figure 9 on page 23 Figure 9 Synchronous Routing to Multiple Destinations PXI_CLK10 Trigger Destination 2 Trigger Destination 1 Trigger Out Source Trigger Synchronously Received Destinations 1 and 2 A B A Pro...

Page 24: ...tions simultaneously you must ensure that the input is table within the setup and hold window around the synchronization clock edge For more information and possible methods to ensure this requirement is met go to ni com info and enter the Info Code SyncTriggerRouting Possible sources for synchronous routing with the PXIe 6674 include the following sources Any front panel PFI pin as single ended A...

Page 25: ...ncy The OCXO frequency can be varied over a small range The output frequency of the OCXO is adjusted using this constant to meet the specification listed in the PXIe 6674 Specifications PXI_CLK10 Phase When using the PLL to lock PXI_CLK10 to an external reference clock the phase between the clocks can be adjusted The time between rising edges of PXI_CLK10 and the input clock is minimized using thi...

Page 26: ...tic environment Operation of this hardware in a residential area is likely to cause harmful interference Users are required to correct the interference at their own expense or cease operation of the hardware Changes or modifications not expressly approved by National Instruments could void the user s right to operate the hardware under the local regulatory rules Caution To ensure the specified EMC...

Page 27: ... Warranty This Limited Warranty does not apply if the defect of the product resulted from improper or inadequate maintenance installation repair or calibration performed by a party other than NI unauthorized modification improper environment use of an improper hardware or software key improper use or operation outside of the specification for the product improper voltages accident abuse or neglect...

Page 28: ...National Instruments _Legal Information txt for information on including legal information in installers built with NI products U S Government Restricted Rights If you are an agency department or other entity of the United States Government Government the use duplication reproduction release modification disclosure or transfer of the technical data included in this manual is governed by the Restri...

Page 29: ...and xPC TargetBox are registered trademarks and Simulink Coder TargetBox and Target Language Compiler are trademarks of The MathWorks Inc Tektronix Tek and Tektronix Enabling Technology are registered trademarks of Tektronix Inc The Bluetooth word mark is a registered trademark owned by the Bluetooth SIG Inc The ExpressCard word mark and logos are owned by PCMCIA and any use of such marks by Natio...

Page 30: ...ND SHUT DOWN MECHANISMS NI EXPRESSLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS OF THE PRODUCTS OR SERVICES FOR HIGH RISK USES Information is subject to change without notice Refer to the NI Trademarks and Logo Guidelines at ni com trademarks for information on NI trademarks Other product and company names mentioned herein are trademarks or trade names of their respective companies For p...

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