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National Instruments PXI-6683 Series Скачать руководство пользователя страница 37

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NI PXI-6683 Series User Manual

The embedded GPS receiver in the NI PXI-6683 Series device requires signals from several
satellites to compute accurate timing and location. The more satellites available to the receiver,
the more accurately it can determine time and location. Therefore, the antenna location should
be such that it receives signals from the greatest number of satellites possible. As the number of
satellites visible to the antenna decreases, the synchronization performance may also decrease.
Choose the antenna location so that the antenna has a clear view of the sky. There is no strict
definition for a clear view of the sky, but a suitable guideline is that the GPS antenna should have
a straight line of sight to the sky in all directions (360°) down to an imaginary line making a 30°
angle with the ground. Locations far from trees and tall buildings that could block or reflect GPS
satellite signals are best.

Maximum Cable Length

Maximum cable length depends on the GPS antenna gain and the cable’s loss per unit of
distance. National Instruments recommends a GPS signal strength of between -135 dBm and
-120 dBm at the NI PXI-6683 Series device SMB input. GPS signal strength on the Earth’s
surface is typically -130 dBm. Targeting a signal strength of -125 dBm at the SMB input, you
can compute the maximum cable length as:

Max_cable_loss = -130 dBm + antenna_gain - (-125 dBm)
Max_cable_length = Max_cable_loss / (loss_per_unit_of_distance)

For example, if you use an active antenna with gain of 28 dB and RG-58 cable, which has a rated
loss at 1.5 GHz of about 0.8 dB/m (24.5 dB/100 ft), the maximum cable length you could use is:

Max_cable_loss = -130 dBm + 28 dB - (-125 dBm) = 23 dB
Max_cable_length = 23 dB / (0.8 dB/m) ≈ 29 m

Note

The GPS antenna kit offered by National Instruments comes with a 30 m

cable which has a loss of 15 dB/100 ft, making the total loss in the cable
approximately 14.8 dB.

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Содержание PXI-6683 Series

Страница 1: ...PXI NI PXI 6683 Series User Manual NI PXI 6683 and NI PXI 6683H Timing and Synchronization Modules for PXI NI PXI 6683 Series User Manual July 2017 373656B 01...

Страница 2: ...email addresses and current events National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA Tel 512 683 0100 For further support information refer to the N...

Страница 3: ...TLE OR NON INFRINGEMENT AND ANY WARRANTIES THAT MAY ARISE FROM USAGE OF TRADE OR COURSE OF DEALING NI DOES NOT WARRANT GUARANTEE OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF OR THE RESULTS OF THE...

Страница 4: ...ependent from NI and have no agency partnership or joint venture relationship with NI Patents For patents covering NI products technology refer to the appropriate location Help Patents in your softwar...

Страница 5: ...6683 Series Front Panel 3 3 GPS LED 3 4 1588 LED 3 4 Ethernet Speed LED 3 5 Ethernet ACT LINK LED 3 5 Connectors 3 5 Hardware Features 3 6 Clock and Event Generation 3 8 TCXO PXI_CLK10 and Clock Disci...

Страница 6: ...3 Synchronization Best Practices 4 3 Operating Environment 4 3 Timing System Performance 4 3 IEEE 1588 Synchronization Best Practices 4 4 Network Topology 4 4 GPS Synchronization Best Practices 4 4 An...

Страница 7: ...tion 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...

Страница 8: ...giving full PXI timing slot functionality The NI PXI 6683H is designed to allow installation in a hybrid slot in a PXI Express system this means some of the PXI Timing slot features are not available...

Страница 9: ...any way Do not install a damaged module into the computer Store the NI PXI 6683 Series in the antistatic envelope when not in use Software Programming Choices The NI PXI 6683 Series uses NI Sync soft...

Страница 10: ...h The product must be completely dry and free from contaminants before you return it to service Operate the product only at or below Pollution Degree 2 Pollution is foreign matter in a solid liquid or...

Страница 11: ...vided by a standard wall outlet for example 115 V for U S or 230 V for Europe Examples of Installation Category II are measurements performed on household appliances portable tools and similar product...

Страница 12: ...s module in the system controller slot slot 1 of a chassis 2 Choose an available slot in the chassis Refer to Table 2 1 for more information about functionality NI PXI 6683 Install the NI PXI 6683 in...

Страница 13: ...and power on the chassis The NI PXI 6683 Series module is now installed Verifying the Installation During the first boot following the software and hardware installation of the NI PXI 6683 Series modu...

Страница 14: ...re Overview This chapter presents an overview of the hardware functions of the NI PXI 6683 Series shown in Figure 3 1 Figure 3 1 Isometric View of the NI PXI 6683 Series 1 NI PXI 6683 2 NI PXI 6683H 1...

Страница 15: ...3 2 The NI PXI 6683H does not have the CLKIN circuitry or the ability to drive PXI_CLK10_IN Synchronization Clock Generation and Routing Circuitry PCI Interface PXI PCI PXI_STAR 0 12 PXI_TRIG 0 7 PXI...

Страница 16: ...6683 Series Figure 3 3 NI PXI 6683 Front Panel Note The NI PXI 6683H does not have the CLKIN connector shown as item 5 in Figure 3 3 1 GPS LED 2 1588 LED 3 GPS Antenna Connector 4 CLKOUT Connector 5...

Страница 17: ...Status Off Not using GPS Amber Attempting to start self survey Blinking Amber Self survey in progress Blinking Green Self survey complete normal operation Red Error The GPS LED is turned off if GPS is...

Страница 18: ...ion describes the connectors on the front panel of the NI PXI 6683 Series Refer to Figure 3 3 for the location of the connectors GPS ANT GPS antenna RF input and DC power output for active GPS antenna...

Страница 19: ...e device driving the AM signal or both Always ensure the line is configured for IRIG B AM operation before connecting an IRIG B AM signal RJ 45 Ethernet 10 100 1000 Mbit Ethernet connection This conne...

Страница 20: ...iming slot can replace this signal with PXI_CLK10_IN Oscillator N A This is the output of the 10 MHz TCXO It is used by the FPGA for synchronization An NI PXI 6683 in the system timing slot can be rou...

Страница 21: ...tains circuitry to measure the temperature of the oscillator and adjust the oscillator s control voltage to compensate for temperature variations according to the crystal s known frequency variation a...

Страница 22: ...a clock generated in this way Refer to Table 3 6 for a list of destinations for synchronized time clocks and future time events PXI_CLK10 Synchronization Design Recommendations Minimize Starting Stop...

Страница 23: ...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 versus asynchron...

Страница 24: ...front panel PFI output signals use 3 3 V signaling for high impedance loads You can use the PFI terminals to generate future time events and clock signals up to 1 5 MHz PFI output Table 3 6 Sources an...

Страница 25: ...rt Ground to get a logic high The PFI trigger outputs may be synchronized to CLK10 except when routing future time events Refer to the Choosing the Type of Routing section for more information about t...

Страница 26: ...e guidelines Whenever timestamping begins on PFI0 either ensure the input will remain at a logic low state for at least 5 ms or disregard timestamps for at least 5 ms When setting up PFI0 as an output...

Страница 27: ...This 10 MHz signal can be sourced from the native PXI backplane oscillator or from the system timing slot Controller Module installed in the system timing slot such as the NI PXI 6683 The following s...

Страница 28: ...source can be independently selected from the following options PFI 0 2 Another PXI trigger line PXI_TRIG 0 7 PXI_STAR 0 12 Future time events PXI_CLK10 Ground Tip Invert Ground to get a logic high Th...

Страница 29: ...ions for choosing each type Asynchronous Routing Asynchronous routing is the most straightforward method of routing signals Any asynchronous route can be defined in terms of two signal locations a sou...

Страница 30: ...nd to get a logic high The destination of an asynchronous routing operation on the NI PXI 6683 Series can be any of the following lines Any front panel PFI pin PFI 0 2 Any PXI star trigger line PXI_ST...

Страница 31: ...logic high state within a window of time around the clock edge This window of time around the clock edge is defined by the setup time tsetup and hold time thold If the input signal changes within thi...

Страница 32: ...o ensure this requirement is met go to ni com info and enter Info Code SyncTriggerRouting Possible sources and destinations for synchronous routing include the following Any front panel PFI pin PFI 0...

Страница 33: ...e per second PPS that the NI PXI 6683 Series uses to achieve sub microsecond synchronization GPS enables the NI PXI 6683 Series to synchronize PXI systems located far away from each other as long as G...

Страница 34: ...hen roll over to 0 Hours begin every day at 0 increment to 23 and then roll over to 0 Days begin every year at 1 Days increment to 365 in non leap years or to 366 in leap years and then roll over to 1...

Страница 35: ...onization performance Operating Environment In order to achieve the best synchronization performance refer to the following guidelines to provide a thermally stable environment Also ensure you remain...

Страница 36: ...d Ethernet switches can have Ethernet packet latencies vary by hundreds of nanoseconds This latency uncertainty degrades synchronization performance significantly Ensure that the network is running at...

Страница 37: ...tions far from trees and tall buildings that could block or reflect GPS satellite signals are best Maximum Cable Length Maximum cable length depends on the GPS antenna gain and the cable s loss per un...

Страница 38: ...constant is then stored in on board non volatile memory along with other calibration metadata such as calibration date and temperature The calibration constant is used at start up when the board is co...

Страница 39: ...ay 11 ns typical Jitter added to CLKIN 1 3 psrms 10 Hz to 100 kHz typical Duty cycle distortion of CLKIN to PXI_CLK10_IN 1 typical Required input duty cycle2 45 to 55 1 When configured to route the on...

Страница 40: ...KOUT when configured to route PXI_CLK10 Output current 48 mA max Square wave rise fall time 10 to 90 for 50 load 1 ns typical Input Characteristics3 Frequency range DC to 50 MHz Input impedance 1 k no...

Страница 41: ...n configured to route PXI_CLK10 IRIG B Input Characteristics PFI0 IRIG B AM compatibility IRIG B 12X 200 04 standard Maximum Input voltage range 5 V to 5 V Input impedance 5 k Decode Input voltage ran...

Страница 42: ...s 2009 If the year is not supplied sent as 00 the OS system time is read and the year is derived from it To achieve proper synchronization of the NI PXI 6683 Series ensure that the IRIG B source used...

Страница 43: ...for timestamping 22 ns TCXO Characteristics Nominal frequency 10 MHz Accuracy within 1 year of calibration adjustment within 0 C to 55 C operating temperature range 3 5 ppm Long term stability 1 ppm...

Страница 44: ...Input impedance 50 nominal GPS receiver type 50 channels GPS L1 frequency 1575 42 MHz C A Code Recommended signal strength at SMB connector 130 dBm Maximum RF power at input 3 dBm Accuracy PPS1 15 ns...

Страница 45: ...50 one standard RJ 45 Ethernet connector NI PXI 6683H Five SMB male 50 one standard RJ 45 Ethernet connector Front panel indicators Two tricolor LEDs green red and amber for GPS and IEEE 1588 status a...

Страница 46: ...15 minutes before PPS offset recording began All test durations were at least 12 hours For the GPS test two NI PXI 6683 Series boards were independently synchronizing to GPS and configured to generate...

Страница 47: ...068 2 56 Shock and Vibration Operational Shock 30 g peak half sine 11 ms pulse Tested in accordance with IEC 60068 2 27 Test profile developed in accordance with MIL PRF 28800F Random Vibration Operat...

Страница 48: ...ltage Directive safety 2004 108 EC Electromagnetic Compatibility Directive EMC Online Product Certification Refer to the product Declaration of Conformity DoC for additional regulatory compliance info...

Страница 49: ...WEEE recycling center For more information about WEEE recycling centers National Instruments WEEE initiatives and compliance with WEEE Directive 2002 96 EC on Waste and Electronic Equipment visit ni c...

Страница 50: ...the signal used to transmit the data and the actual data transmitted This is usually specified by 3 digits that follow the IRIG standard name for instance IRIG B 120 Table B 2 details the different c...

Страница 51: ...ion and at space for the remaining 20 Binary bits are used to transmit information such as time of year straight binary seconds and so on and position identifiers are used to separate the different pi...

Страница 52: ...osition identifier The figure shows the information transmitted using an amplitude modulated signal and a pulse width modulated signal Figure B 1 IRIG B AM and DC Transmission Example IRIG B is one of...

Страница 53: ...ction bits 59 Position identifier P6 60 to 68 Control function bits 69 Position identifier P7 70 to 78 Control function bits 79 Position identifier P8 80 to 88 Nine lowest significant bits of time of...

Страница 54: ...B signal All conditions must be met for the NI PXI 6683 Series to be able to synchronize accurately Seconds begin every minute at 0 increment to 59 and then roll over to 0 Minutes begin every hour at...

Страница 55: ...y your systems accuracy and reliability requirements and provides warranty sparing and calibration services to help you maintain accuracy and minimize downtime over the life of your system Visit ni co...

Страница 56: ...tions Engineers make sure every question submitted online receives an answer Software Support Service Membership The Standard Service Program SSP is a renewable one year subscription included with alm...

Страница 57: ...lli 10 3 k kilo 103 M mega 106 Symbols percent plus or minus positive of or plus negative of or minus per degree ohm A AC alternating current ADE application development environment asynchronous a pro...

Страница 58: ...XI_CLK10_IN CLKOUT CLKOUT is the signal on the SMB output pin of the same name PXI_CLK10 can be routed to CLKOUT clock hardware component that controls timing for reading from or writing to groups Com...

Страница 59: ...ter DC direct current E ESD electrostatic discharge F frequency the basic unit of rate measured in events or oscillations per second using a frequency counter or spectrum analyzer Frequency is the rec...

Страница 60: ...urement Automation Explorer MAX a controlled centralized configuration environment that allows you to configure all of your National Instruments DAQ GPIB IMAQ IVI Motion VISA and VXI devices O oscilla...

Страница 61: ...the amount of time required for a signal to pass through a circuit PXI a rugged open system for modular instrumentation based on CompactPCI with special mechanical electrical and software features Th...

Страница 62: ...slot the place in the computer or chassis in which a card or module can be installed SMB sub miniature type B a small coaxial signal connector that features a snap coupling for fast connection synchro...

Страница 63: ...D color explanation table 3 5 configuring the device Ethernet Speed LED 3 5 overview 2 2 D Declaration of Conformity NI resources C 1 destinations possible destinations table 3 11 diagnostic tools NI...

Страница 64: ...nization 4 1 best practices 4 3 GPS 4 1 IEEE1588 4 2 IRIG B 4 1 PPS 4 2 help technical support C 1 I I O considerations 3 11 I O terminals table 3 7 IEEE 1588 synchronization 4 2 best practices 4 4 ne...

Страница 65: ...sources and destinations table 3 11 PXI star triggers 3 15 PXI triggers 3 14 overview 3 13 types asynchronous 3 16 synchronous 3 17 S safety specifications A 8 shock and vibration specifications A 8 s...

Страница 66: ...ized future time clock generation specifications A 4 synchronous routing overview 3 17 timing diagram 3 18 T TCXO clock generation 3 8 overview 3 8 specifications A 5 technical support C 1 temperature...

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