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NEO-D9S - Integration manual

3 Receiver functionality

This section describes the NEO-D9S operational features and their configuration.

3.1 Receiver configuration

u-blox positioning receivers are fully configurable with UBX protocol messages. The configuration
used  by  the  receiver  during  normal  operation  is  called  the  "current  configuration".  The  current
configuration can be changed during normal operation by sending UBX configuration messages. On
start-up the current configuration held in RAM is built from the default firmware settings plus any
settings held in flash memory.

Configuration interface settings are held in a database consisting of separate configuration items.
An item is made up of a pair consisting of a key ID and a value. Related items are grouped together
and  identified  under  a  common  group  name:  CFG-GROUP-*;  a  convention  used  in  u-center  and
within this document. Within u-center, a configuration group is identified as "Group name" and the
configuration item is identified as the "item name" under the "Generation 9 Configuration View" -
"Advanced Configuration" view.

The UBX messages available to change or poll the configurations are the UBX-CFG-VALSET, UBX-
CFG-VALGET, and UBX-CFG-VALDEL messages. For more information about these messages and
the configuration keys see the configuration interface section in the applicable interface description
[

2

].

3.1.1 Changing the receiver configuration

The  configuration  messages  UBX-CFG-VALSET,  UBX-CFG-VALGET  and  UBX-CFG-VALDEL  will
result in a UBX-ACK-ACK or a UBX-ACK-NAK response.

3.1.2 Default L-band configuration

The default L-band configuration is:

• CFG-PMP-CENTER_FREQUENCY = 1539812500 Hz
• CFG-PMP-SEARCH_WINDOW = 2200 Hz
• CFG-PMP-USE_SERVICE_ID = 1 (true)
• CFG-PMP-SERVICE_ID = 50821
• CFG-PMP-DATA_RATE = 2400 (B2400) bps
• CFG-PMP-USE_DESCRAMBLER = 1 (true)
• CFG-PMP-DESCRAMBLER_INIT = 23560
• CFG-PMP-UWERRT = 4
• CFG-PMP-USE_PRESCRAMBLING = 0 (false)
• CFG-PMP-UNIQUE_WORD = 0xe15ae893e15ae893

The required satellite center frequency and service data rate might need changing based on
the receiver global location to aid acquisition of the required satellite/service (service ID).

The configuration settings can be modified using UBX protocol configuration messages. For more
information, see the applicable Interface description [

2

].

3.1.3 Default interface settings

Interface

Settings

UART

9600 baud, 8 bits, no parity bit, 1 stop bit.

UBX-19026111 - R07

 

3 Receiver functionality

Page 7 of 52

C1-Public

Содержание NEO-D9S

Страница 1: ... D9S u blox D9 correction data receiver Integration manual Abstract This document describes the features and specifications of the u blox D9 correction data receiver www u blox com UBX 19026111 R07 C1 Public ...

Страница 2: ...ty rights in the products names logos and designs included in this document Copying reproduction modification or disclosure to third parties of this document or any part thereof is only permitted with the express written permission of u blox The information contained herein is provided as is and u blox assumes no liability for its use No warranty either express or implied is given including but not...

Страница 3: ... 4 USB interface 16 3 3 Predefined PIOs 17 3 3 1 D_SEL 17 3 3 2 RESET_N 17 3 3 3 SAFEBOOT_N 17 3 3 4 TX_READY 18 3 3 5 EXTINT 18 3 4 Antenna supervisor 19 3 4 1 Antenna voltage control ANT_OFF 20 3 4 2 Antenna short detection ANT_SHORT_N 20 3 4 3 Antenna short detection auto recovery 21 3 4 4 Antenna open circuit detection ANT_DETECT 21 3 5 Security 22 3 5 1 Receiver status monitoring 22 3 6 Forcin...

Страница 4: ...34 4 7 3 Package footprint copper and paste mask 34 4 7 4 Layout guidance 36 4 8 Design guidance 38 4 8 1 General considerations 38 4 8 2 RF front end circuit options 38 4 8 3 Antenna RF input 39 4 8 4 Schematic design 39 4 8 5 Layout design in guideline 40 5 Product handling 41 5 1 ESD handling precautions 41 5 2 Soldering 41 5 3 Tapes 44 5 4 Reels 45 5 5 Moisture sensitivity levels 45 Appendix 4...

Страница 5: ...ortant source of information on all aspects of u blox D9 correction data receiver The purpose of this document is to provide guidelines for a successful integration of the receiver with the customer s end product UBX 19026111 R07 1 Integration manual overview Page 5 of 52 C1 Public ...

Страница 6: ...s their correction coverage area is accessible via a satellite and not simply broadcast over large areas of the earth with no feasible use Each service provider will be allocated a correction service ID and a frequency for a particular part of the globe In addition the service provider will have a data bit rate for their data stream This means that the frequency allocation for a particular service...

Страница 7: ...nge or poll the configurations are the UBX CFG VALSET UBX CFG VALGET and UBX CFG VALDEL messages For more information about these messages and the configuration keys see the configuration interface section in the applicable interface description 2 3 1 1 Changing the receiver configuration The configuration messages UBX CFG VALSET UBX CFG VALGET and UBX CFG VALDEL will result in a UBX ACK ACK or a UBX A...

Страница 8: ...tails The configuration groups available for each interface are Interface Configuration groups UART1 CFG UART1 CFG UART1INPROT CFG UART1OUTPROT UART2 CFG UART2 CFG UART2INPROT CFG UART2OUTPROT USB CFG USB CFG USBINPROT CFG USBOUTPROT I2C CFG I2C CFG I2CINPROT CFG I2COUTPROT SPI CFG SPI CFG SPIINPROT CFG SPIOUTPROT Table 2 Interface configurations 3 1 4 2 Message output configuration The rate of the su...

Страница 9: ...quired that can be configured from the information supplied by the service provider The receiver will output raw L band correction data when a service provider satellite data frame is received This will be output in the UBX RXM PMP message This message is not output at a fixed rate If no selected service provider data frame is detected no UBX RXM PMP message is sent The output rate of the UBX RXM PM...

Страница 10: ... of CPU activity to avoid breaching requirements of the USB specification The drawback however is that power consumption is higher Wake up by N_RESET EXTINT pin or UART RX is possible even if the receiver is connected to a USB host In this case the state of the pin must be changed for a duration longer than one millisecond 3 2 Communication interfaces u blox receivers are equipped with a communicat...

Страница 11: ...ration monitoring and control UART2 may be used to provide correction data directly to a high precision GNSS receiver from the u blox F9 platform To check whether a specific u blox F9 product supports correction data output by the NEO D9S refer to its Integration manual The UART RX interface will be disabled when more than 100 frame errors are detected during a one second period This can happen if ...

Страница 12: ... kb s The SCL and SDA pins have internal pull up resistors which should be sufficient for most applications However depending on the speed of the host and the load on the I2C lines additional external pull up resistors may be necessary To use the I2C interface D_SEL pin must be left open In designs where the host uses the same I2C bus to communicate with more than one u blox receiver the I2C slave a...

Страница 13: ... the random access form of the request Following the start condition from the master the 7 bit device address and the RW bit which is a logic low for write access are clocked onto the bus by the master transmitter The receiver answers with an acknowledge logic low to indicate that it recognizes the address Next the 8 bit address of the register to be read must be written to the bus Following the r...

Страница 14: ...ss The receiver does not provide any write access except for writing UBX and NMEA messages to the receiver such as configuration or aiding data Therefore the register set mentioned in the section Read access is not writeable Following the start condition from the master the 7 bit device address and the RW bit which is a logic low for write access are clocked onto the bus by the master transmitter T...

Страница 15: ...To prevent the receiver from being busy parsing incoming data the parsing process is stopped after 50 subsequent bytes containing 0xFF The parsing process is re enabled with the first byte not equal to 0xFF If the receiver has no more data to send it sets MISO to logic high i e all bytes transmitted decode to 0xFF An efficient parser in the host will ignore all 0xFF bytes which are not part of a mess...

Страница 16: ...SB to ground and leave data lines open when the USB interface is not used in an application The voltage range for V_USB is specified from 3 0 V to 3 6 V which differs slightly from the specification for VCC The boot screen is retransmitted on the USB port after enumeration However messages generated between boot up of the receiver and USB enumeration are not visible on the USB port There are addition...

Страница 17: ...9 SPI_CLK I2C SCL Table 4 D_SEL configuration 3 3 2 RESET_N The NEO D9S provides the ability to reset the receiver The RESET_N pin is an input only pin with an internal pull up resistor Driving RESET_N low for at least 100 ms will trigger a cold start The RESET_N pin will delete all information and trigger a cold start It should only be used as a recovery option 3 3 3 SAFEBOOT_N The NEO D9S provide...

Страница 18: ...ely associated to one port and cannot be shared If PIO is invalid or already in use only the configuration for the specific TX_READY pin is ignored the rest of the port configuration is applied if valid The acknowledge message does not indicate if the TX READY configuration is successfully set it only indicates the successful configuration of the port To validate successful configuration of the TX_READY...

Страница 19: ... ANT_DET ANT_OFF ANT_SHORT_N pins For an example the open circuit detection circuit using ANT_DET high Antenna detected antenna consumes current low Antenna not detected no current drawn The following schematic details the required circuit and the sections following it explain how to enable and monitor each feature Figure 11 NEO D9S antenna supervisor The bias t inductor must be chosen for multi b...

Страница 20: ...ontrol is activated 3 4 2 Antenna short detection ANT_SHORT_N Enable the antenna short detection by setting the configuration item CFG HW ANT_CFG_SHORTDET to true 1 Result UBX MON RF in u center Message View Antenna status OK Antenna power status ON ANT_OFF active high to disable an external antenna therefore the pin is low to enable an external antenna ANT_SHORT_N active low to detect a short ther...

Страница 21: ... SR Then if antenna is shorted ANT_SHORT_N pulled low GNTXT 01 01 02 ANTSTATUS SHORT 73 UBX MON RF in u center Message View Antenna status SHORT Antenna power status OFF ANT_OFF high to disable active high After a time out period receiver will re test the short condition by enabling ANT_OFF LOW If a short is not present it will report antenna condition is OK GNTXT 01 01 02 ANTSTATUS OK 25 UBX MON ...

Страница 22: ... not related to L band but to the way the software restarts the system Hardware reset watchdog immediately uses the on chip watchdog in order to electrically reset the chip This is an immediate asynchronous reset No Stop events are generated Controlled software reset terminates all running processes in an orderly manner and once the system is idle restarts operation reloads its configuration and st...

Страница 23: ...re 12 NEO D9S pin assignment Pin no Name I O Description 1 SAFEBOOT_N I SAFEBOOT_N used for FW updates and reconfiguration leave open 2 D_SEL I UART 1 SPI select open or high UART 1 3 TXD2 O UART 2 TXD 4 RXD2 I UART 2 RXD 5 USB_DM I O USB data DM 6 USB_DP I O USB data DP 7 V_USB I USB supply 8 RESET_N I RESET active low 9 VCC_RF O External LNA power 10 GND I Ground 11 RF_IN I Active antenna L band ...

Страница 24: ...D_SEL GND 21 RXD SPI MOSI I UART1 input if D_SEL VCC or open SPI MOSI if D_SEL GND 22 V_BCKP I Connect to VCC or leave it open 23 VCC I Supply voltage 24 GND I Ground Table 6 NEO D9S pin assignment 4 2 Antenna An active antenna is mandatory with the NEO D9S The NEO D9S needs to receive L band signals in order to operate A separate L band antenna should be used to meet the requirement of 4 dBic pat...

Страница 25: ...rovide correction data directly to a high precision GNSS receiver from the u blox F9 platform To check whether a specific u blox F9 product supports correction data output by the NEO D9S refer to its Integration manual Recommended single L band antenna required specifications Parameter Specification Antenna type Active antenna Typical gain 30 dB Maximum gain 40 dB Active antenna recommendations Maxim...

Страница 26: ...m over elevation azimuth Group delay variation in band 5 10 ns max at each GNSS system bandwidth Note Inter signal requirement 50 ns max EMI immunity out of band 3 30 V m Out of band 5 Rejection 4 40 dB typ NEO D9S 00A NEO D9S 00B 65 dB min NEO D9S 01A ESD circuit protection 15 kV human body model air discharge Table 8 Antenna specifications for NEO D9S modules The NEO D9S 01A antenna requirement i...

Страница 27: ...nded bias t inductor Murata LQG15HS47NJ02 has a maximum current capacity of 300 mA Hence the current is limited to 70 mA at 3 3V using an active limiter in the recommended circuit shown in Figure 16 below A 10 Ω resistor R2 is provided to measure the current This resistor power rating must be chosen to ensure reliability in the chosen circuit design Figure 15 NEO D9S antenna bias inductor impedanc...

Страница 28: ...g is not used the important points covered below need to be taken into account Figure 17 NEO D9S VCC_RF antenna bias The bias t inductor and current limiting resistor must be selected to be reliable with a short circuit on the antenna feed if no active current limiter is used Our recommended part has a limit of 300 mA A part with a higher current capability will be needed if the short circuit curr...

Страница 29: ...ility is part of the calculation Figure 18 NEO D9S external voltage antenna bias 4 3 Power supply The u blox NEO D9S module has two power supply pins VCC and V_USB 4 3 1 VCC Main supply voltage The VCC pin is connected to the main supply voltage During operation the current drawn by the module can vary by some orders of magnitude For this reason it is important that the supply circuitry be able to...

Страница 30: ...ing the UART1 interface is shown below Figure 20 Minimal NEO D9S design It is important to connect V_USB to ground if USB is not used Connect the power supply to VCC UART2 may be used to provide correction data directly to a high precision GNSS receiver from the u blox F9 platform To check whether a specific u blox F9 product supports correction data output by the NEO D9S refer to its Integration m...

Страница 31: ...4 5 1 ESD protection measures L band receivers are sensitive to Electrostatic Discharge ESD Special precautions are required when handling Most defects caused by ESD can be prevented by following strict ESD protection rules for production and handling When implementing passive antenna patches or external antenna connection points then additional ESD measures as shown in the figure below can also av...

Страница 32: ...and antenna EMI protection measures are particularly useful when RF emitting devices are placed next to the L band receiver and or to minimize the risk of EMI degradation due to self jamming An adequate layout with a robust grounding concept is essential in order to protect against EMI Intended Use In order to mitigate any performance degradation of a radio equipment under EMC disturbance system i...

Страница 33: ... guaranteed even under interference conditions In such a case not only the maximum power ratings of the components in the receiver RF path must be observed Further non linear effects like gain compression NF degradation desensitization and intermodulation must be analyzed Pulsed interference with a low duty cycle such as GSM may be destructive due to the high peak power levels 4 6 2 In band interfe...

Страница 34: ...g through its GND plane 4 7 2 Thermal management During design in do not place the receiver near sources of heating or cooling The receiver oscillator is sensitive to sudden changes in ambient temperature which can adversely impact satellite signal tracking Sources can include co located power devices cooling fans or thermal conduction via the PCB Take into account the following questions when des...

Страница 35: ...Integration manual 4 7 3 1 Mechanical dimensions Figure 23 NEO D9S mechanical dimensions 4 7 3 2 Footprint Figure 24 NEO D9S suggested footprint i e copper mask UBX 19026111 R07 4 Design Page 35 of 52 C1 Public ...

Страница 36: ...7 4 Layout guidance The presented layout guidance reduces the risk of performance issues at design level 4 7 4 1 RF In trace The RF In trace has to work in the middle L band frequencies For FR 4 PCB material with a dielectric permittivity of for example 4 7 the trace width for the 50 Ω line impedance can be calculated Figure 26 Microstrip trace width A grounded co planar RF trace is recommended as...

Страница 37: ...d by vias to ground along the entire length of the trace and the NEO D9S RF_IN pad should be surrounded by vias as shown in the figure below Figure 28 RF input trace The RF_IN trace on the top layer should be referenced to a suitable ground layer UBX 19026111 R07 4 Design Page 37 of 52 C1 Public ...

Страница 38: ...L band module with the specification of your power supply L band receivers require a stable power supply Avoid series resistance less than 0 2 Ω in your power supply line the line to VCC to minimize the voltage ripple on VCC See the NEO D9S Power supply section in the Design chapter for more information on the power supply requirements All I O including UART must not be pulled high before power ON ...

Страница 39: ...on in front of RF_IN is mandatory to avoid device destruction ESD discharge cannot be avoided during assembly and or field use Note that SAW filters are susceptible to ESD damage To provide additional robustness an ESD protection diode may be placed at the antenna RF connector to GND 4 8 3 Antenna RF input Check RF input requirements and schematic With the NEO D9S L band module an active antenna mee...

Страница 40: ... effects of air currents and rapid environmental temperature changes Is the receiver placed as recommended in the Layout and Layout guidance Assure a low serial resistance on the VCC power supply line choose a line width 400 um Keep the power supply line as short as possible Add a ground plane underneath the module to reduce interference This is especially important for the RF input line For improv...

Страница 41: ... antenna area is touched in non ESD protected work area implement proper ESD protection measures in the design When soldering RF connectors and patch antennas to the receiver s RF pin make sure to use an ESD safe soldering iron tip 5 2 Soldering Soldering paste Use of no clean soldering paste is highly recommended as it does not require cleaning after the soldering process The paste in the example...

Страница 42: ...rature rises above the liquidus temperature of 217 C Avoid a sudden rise in temperature as the slump of the paste could become worse Limit time above 217 C liquidus temperature 40 60 s Peak reflow temperature 245 C Cooling phase A controlled cooling prevents negative metallurgical effects of the solder solder becomes more brittle and possible mechanical tensions in the products Controlled cooling he...

Страница 43: ...nently damage the module in particular the quartz oscillators The best approach is to use a no clean soldering paste and eliminate the cleaning step after the soldering Repeated reflow soldering Repeated reflow soldering processes or soldering the module upside down are not recommended A board that is populated with components on both sides may require more than one reflow soldering cycle In such a c...

Страница 44: ...oid the warranty Casting If casting is required use viscose or another type of silicon pottant The OEM is strongly advised to qualify such processes in combination with the module before implementing this in the production Casting will void the warranty Grounding metal covers Attempts to improve grounding by soldering ground cables wick or other forms of metal strips directly onto the EMI covers i...

Страница 45: ...D9S tape dimensions mm 5 4 Reels The NEO D9S receivers are deliverable in quantities of 250 pieces on a reel The receivers are shipped on reel type B as specified in the u blox Package Information Guide 3 5 5 Moisture sensitivity levels The moisture sensitivity level MSL for NEO D9S is specified in the table below UBX 19026111 R07 5 Product handling Page 45 of 52 C1 Public ...

Страница 46: ... Table 10 MSL level For MSL standard see IPC JEDEC J STD 020 which can be downloaded from www jedec org For more information regarding moisture sensitivity levels labeling storage and drying see the u blox Package Information Guide 3 UBX 19026111 R07 5 Product handling Page 46 of 52 C1 Public ...

Страница 47: ... A successful calibration can be made if the phase variation of a specific antenna is repeatable between samples To obtain the best antenna performance in an automotive application mount the antenna in the center of a conductive car roof without any inclination The antenna requires good signal levels and as wide a view of the sky as possible The antenna must not be placed under a dashboard in the r...

Страница 48: ...American National Standards Institute ARP Antenna reference point BeiDou Chinese navigation satellite system BBR Battery backed RAM CDMA Code division multiple access EMC Electromagnetic compatibility EMI Electromagnetic interference EOS Electrical overstress EPA Electrostatic protective area ESD Electrostatic discharge Galileo European navigation satellite system GLONASS Russian navigation satell...

Страница 49: ...Global System for Mobile Communications I2C Inter integrated circuit bus IEC International Electrotechnical Commission PCB Printed circuit board PMP Point to multipoint transmission QZSS Quasi Zenith Satellite System RF Radio frequency SV Space vehicle a satellite UBX u blox UBX 19026111 R07 Appendix Page 49 of 52 C1 Public ...

Страница 50: ...sheet UBX 21008860 2 PMP 1 04 Interface description UBX 21040023 3 Packaging information for u blox chips modules and antennas UBX 14001652 For regular updates to u blox documentation and to receive product change notifications please register on our homepage https www u blox com UBX 19026111 R07 Related documents Page 50 of 52 C1 Public ...

Страница 51: ...tion I2C address changed R04 19 Feb 2020 ghun NEO D9S 00B Early production information Tape dimension picture updated missing tape picture added R05 13 Oct 2020 ghun dama USB interface section update Add C N0 specification in antenna section Add C N0 levels limits in production testing section R06 22 Oct 2021 dama NEO D9S 00A and NEO D9S 01A Advance information R07 24 Jan 2022 dama UART2 interface ...

Страница 52: ...s u blox com E mail info_cn u blox com Support support_cn u blox com Regional Office China Chongqing Phone 86 23 6815 1588 E mail info_cn u blox com Support support_cn u blox com Regional Office China Shanghai Phone 86 21 6090 4832 E mail info_cn u blox com Support support_cn u blox com Regional Office China Shenzhen Phone 86 755 8627 1083 E mail info_cn u blox com Support support_cn u blox com Regional...

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