Globalsat ET-314AC User Manual [ru]

GLOBALSAT GPS Engine Board

Hardware Data Sheet

Product No : ET-314AC

Version 2.2

Issue Date

2010/04/01

2010/4/1

APPR

Ray

Globalsat Technology Corporation

16F., No. 186, Jian-Yi Road, Chung-Ho City, Taipei

Hsien 235, Taiwan

Tel: [phone] Fax: [phone]

E-mail : [e-mail]

Website: www.globalsat.com.tw

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ET-314AC
High Performance GPS Engine Board

Product Description

Product Description

ET-314AC is a compact, high performance, and low power consumption GPS engine board. It
uses SiRF Star III chipset which can track up to 20 satellites at a time and perform fast TTFF in
weak signal environments. ET-314AC is suitable for the following applications:

z Automotive navigation
z Personal positioning
z Fleet management
z Mobile phone navigation
z Marine navigation

Product Features

z SiRF star III high performance GPS Chipset
z Very high sensitivity (Tracking Sensitivity: -159 dBm)
z Extremely fast TTFF (Time To First Fix) at low signal level
z Two serial ports
z 4Mb flash
z Built-in LNA
z Compact size (25.4mm * 25.4 mm * 2.50mm) suitable for space-sensitive application
z One size component, easy to mount on another PCB board

z Support NMEA 0183 V2.3 (Output: GGA, GSA, GSV, RMC, VTG, GLL, ZDA)

z Support SiRF binary protocol
z Active antenna detect

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High Performance GPS Engine Board

Product Block Diagram

Product Pin Description

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PIN Number(s) Name Type Description Note

1 VCC P Main power supply to the engine board.

2,10,30 GND P Ground.

3 BOOTSEL I Set this pin to high for programming flash. 2

This is the main receive channel for receiving

4 RxD0 I

software commands to the engine board from
SiRFdemo software or from user written
software.
This is the main transmits channel for
outputting navigation and measurement data

5 TxD0 O

to user’s navigation software or user written

software. Output TTL level, 0V ~ 2.85V.
6 TxD1 O Serial output (default null)
7 RxD1 I Serial input (default null) 1
8

GPIO14 I/O General purpose I/O

9,25,26 NC ET-314AC reserves PIN

11,12,13,14,

GND_A P GPS RF Ground.

15,16,18

17. RF IN RF GPS antenna input
19 V_ANT I Antenna Bias voltage
20 VCC_RF O Supply Antenna Bias voltage (V=VCC)

1

1,3

21 V_BAT P Backup battery supply voltage
22 RESET I System reset (active low)
23 VDD28OUT O Output voltage 2.85V
24 GPIO1 I/O General purpose I/O 2,3
27 GPIO13 I/O General purpose I/O 1,3
28

GPIO15 I/O

General purpose I/O 1,3

29 1PPS O One pulse per second output. 2,3

<Note>

1. Internal pull-up resistor (100K nominal).

2. Internal pull-down resistor (100K nominal).

3. Default input at reset.

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High Performance GPS Engine Board

Electrical Specification

Absolute Maximums Ratings

Parameter Min. Typ. Max. Conditions Unit
POWER Supply
Main power supply 3.1 3.3 3.5 V
Backup battery supply 2.0 3.5 V
Main power supply Current 23.80 26.24 26.70 mA
Backup battery supply Current 4.5 5.0 12.6 uA
Interface (VCC = 3.3V, VBAT= 3.3V, Operation Temp.= 25℃)

High Level input Voltage 0.7*VDD 3.5 V
Low Level input Voltage -0.3 0.3*VDD V
High Level input Current -10 10

60

Low Level input Current -10 10

-60
High Level output Voltage 0.75*VDD V
Low Level output Voltage 0.25*VDD V
RF Input
Input Impedance 50 
Operating Frequency 1.575 Ghz
☆ VDD is 2.85V for SiRF STARIII CHIP

(V=2.85V)

uA

(with Pull Low)
(V=0V)

uA

(with Pull High)

Receiver Performance

Sensitivity Tracking:-159dBm
Cold Start 42 seconds, average

Warm Start 38 seconds, average

Hot Start 1 second, average

Reacquisition 0.1 second, average

Maximum Altitude

Maximum Velocity

Maximum Acceleration

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Accuracy Position:

10 meters 2D RMS
1-5 meters 2D RMS, WAAS corrected.
Velocity: 0.1 m/s
Time: 1us synchronized to GPS time

＜

18,000 meter

＜

515 meter/ second

＜

4G

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High Performance GPS Engine Board

Environmental Characteristics

Parameter Min Typ Max Unit
Humidity Range 5 95 % non-condensing
Operation Temperature -40 25 85
Storage Temperature -40 85

Physical Characteristic

Type 30-pin stamp holes

Dimensions 25.4 mm *25.4 mm * 2.50 mm ±0.2mm

Package Dimensions

℃
℃

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Application

Application Circuit

POWER Circuit

GPS POWER

VIN

C1

22UF/10V

U1

1

VIN

2
3

XC6209B332MRN 3.3V

VOUT
GND
CE

NC

5

4

C2

10UF/16V

L1

BLM18AG121SN1D

C3

470PF

GPS Active Antenna Specifications (Recommendation)

Frequency: 1575.42 + 2MHz Amplifier Gain: 18~22dB Typical
Axial Ratio: 3 dB Typical Output VSWR: 2.0 Max.
Output Impedance: 50 Noise Figure: 2.0 dB Max

GPS_3V3

Polarization: RHCP Antenna Input Voltage: 2.85V (Typ.)

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OPERATING Description

VCC

This is the main power supply to the engine
board. (3.1Vdc to 3.5Vdc)

GND

This is Ground pin for the baseband circuit.

GND_A

This is Ground pin for the ET-314AC RFand
circuit. To use ET-314AC, GND_A need
connect to GND with L bead or 0 resistor.

RxD0

This is the main channel for receiving
software commands from SiRFdemo
software or from your proprietary software.

TxD0

This is the main transmits channel for
outputting navigation and measurement data
to user’s navigation software or user written

battery voltage should be between 2.0V and

3.5V.

NC

ET-314AC reserves PIN, Just NC.

VDD28OUT

This PIN is output voltage 2.85V. If do not
use it, Just NC.

RESET

This pin is input low active. This Module has
internal Power on Reset circuit.

GPIOs

User can use this I/O pin for special functions
(For example, control LED) .ET-314AC had
GPIO 1 & 13 &14.

VCC_RF

VCC_RF can supply Active Antenna Bias
voltage. This pin will supply Active Antenna.

software. Output is TTL level, 0V ~ 2.85V

RxD1

For user’s application (default null).

TxD1

For user’s application (default null).

RF_IN

This pin receives signal of GPS analog via
external active antenna. It has to be a
controlled impedance trace at 50ohm. Do not
have RF traces closed the other signal path
and routing it on the top layer. Keep the RF
traces as short as possible.

V_BAT

This is the battery backup power input for the
SRAM and RTC when main power is off.
Without the external backup battery,
ET-314AC will always execute a cold star

If do not use it, Just NC.

V_ANT

V_ANT is Active Antenna Bias voltage input.
If you use Active Antenna, you can connect
this pin to VCC_RF or connect other POWER
(Vin = 2.85~5V). If you will be use Passive
Antenna, Just NC.

BOOTSEL

Set this pin to high for programming flash in
debug mode. If need programming
ET-314AC Flash, just pull-up 15K resistor
to 3.3V. When ET-314AC used in normal
function, this pin just NC.

1PPS

This pin provides one pulse-per-second
output from the board, which is synchronized

to GPS time. This is not available in Trickle
after turning on. To achieve the faster
start-up offered by a hot or warm start, a
battery backup must be connected. The

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Power mode

. If do not use it, Just NC.

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High Performance GPS Engine Board

SOFTWARE COMMAND

NMEA Output Command

GGA - Global Positioning System Fixed Data

Note – Fields marked in italic red apply only to NMEA version 2.3 (and later) in this NMEA

message description

Table A-1 contains the values for the following example:

$GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M,,,,0000*18

Table A-1 GGA Data Format

Name Example Units Description
Message ID $GPGGA GGA protocol header
UTC Time 161229.487 hhmmss.sss
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N=north or S=south
Longitude 12158.3416 dddmm.mmmm
E/W Indicator W E=east or W=west
Position Fix Indicator 1 See Table A-2
Satellites Used 07 Range 0 to 12
HDOP 1.0 Horizontal Dilution of Precision
MSL Altitude1 9.0 meters
Units M meters
Geoid Separation1 meters
Units M meters
Age of Diff. Corr. second Null fields when DGPS is not used
Diff. Ref. Station ID 0000
Checksum *18
<CR><LF> End of message termination

Table A-2 Position Fix Indicator

Value Description
0 Fix not available or invalid
1 GPS SPS Mode, fix valid
2 Differential GPS, SPS Mode , fix valid
3-5 Not supported

6 Dead Reckoning Mode, fix valid

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Note – A valid status is derived from all the parameters set in the software. This includes the

minimum number of satellites required, any DOP mask setting, presence of DGPS corrections,
etc. If the default or current software setting requires that a factor is met, then if that factor is not
met the solution will be marked as invalid.

GLL - Geographic Position-Latitude/Longitude

Note – Fields marked in italic red apply only to NMEA version 2.3 (and later) in this NMEA

message description

Table A-3 contains the values for the following example:

$GPGLL,3723.2475,N,12158.3416,W,161229.487,A,A*41

Table A-3 GLL Data Format

Name Example Units Description

Message ID $GPGLL GLL protocol header
Latitude 3723.2475 ddmm.mmmm
N/S Indicator n N=north or S=south
Longitude 12158.3416 dddmm.mmmm
E/W Indicator W E=east or W=west
UTC Position 161229.487 hhmmss.sss
Status A A=data valid or V=data not valid

Mode A A=Autonomous, D=DGPS, E=DR

N=Output Data Not Valid

Checksum *41
<CR><LF> End of message termination

GSA - GNSS DOP and Active Satellites

Table A-4 contains the values for the following example:

$GPGSA,A,3,07,02,26,27,09,04,15,,,,,,1.8,1.0,1.5*33

Table A-4 GSA Data Format

Name Example Units Description
Message ID $GPGSA GSA protocol header

Manual-forced to operate in 2D or 3D mode

M

Mode 1 A

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2Dautomatic-allowed to automatically switch

A

2D/3D

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High Performance GPS Engine Board

1 Fix Not Available

Mode 2 3

22D

33D
Satellite Used1 07 Sv on Channel 1
Satellite Used1 02 Sv on Channel 2
…..
Satellite Used1 Sv on Channel 12
PDOP2 1.8 Position dilution of Precision
HDOP2 1.0 Horizontal dilution of Precision
VDOP2 1.5 Vertical dilution of Precision
Checksum *33
<CR><LF> End of message termination

1. Satellite used in solution.

2. Maximum DOP value reported is 50. When 50 is reported, the actual DOP may be much
larger.

GSV - GNSS Satellites in View

Table A-5 contains the values for the following example:

$GPGSV,2,1,07,07,79,048,42,02,51,062,43,26,36,256,42,27,27,138,42*71
$GPGSV,2,2,07,09,23,313,42,04,19,159,41,15,12,041,42*41

Table A-5 GSV Data Format

Name Example Units Description
Message ID $GPGSV GSV protocol header
Number of

2 Range 1 to 3
Messages1
Message Number1 1 Range 1 to 3
Satellites in View1 07
Satellite ID 07 Channel 1(Range 1 to 32)
Elevation 79 degrees Channel 1(Maximum90)
Azimuth 048 degrees Channel 1(True, Range 0 to 359)
SNR(C/No) 42 dBHz Range 0 to 99,null when not tracking
……. …….
Satellite ID 27 Channel 4 (Range 1 to 32)
Elevation 27 Degrees Channel 4(Maximum90)
Azimuth 138 Degrees Channel 4(True, Range 0 to 359)

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SNR(C/No) 42 dBHz Range 0 to 99,null when not tracking
Checksum *71
<CR><LF> End of message termination

1. Depending on the number of satellites tracked, multiple messages of GSV data may be
required. In some software versions, the maximum number of satellites reported as visible is
limited to 12, even though more may be visible.

RMC - Recommended Minimum Specific GNSS Data

Note – Fields marked in italic red apply only to NMEA version 2.3 (and later) in this NMEA

message description

Table A-6 contains the values for the following example:

$GPRMC,161229.487,A,3723.2475,N,12158.3416,W,0.13,309.62,120598,,*10

Table A-6 RMC Data Format
Name Example Units Description

Message ID $GPRMC RMC protocol header
UTC Time 161229.487 hhmmss.sss
Status1 A A=data valid or V=data not valid
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N=north or S=south
Longitude 12158.3416 dddmm.mmmm
E/W Indicator W E=east or W=west
Speed Over Ground 0.13 knots
Course Over Ground 309.62 degrees True
Date 120598 ddmmyy
Magnetic Variation2 degrees E=east or W=west
East/West Indicator2 E E=east

Mode A A=Autonomous, D=DGPS, E=DR

N=Output Data Not Valid

Checksum *10

<CR><LF> End of message termination

1. A valid status is derived from all the parameters set in the software. This includes the
minimum number of satellites required, any DOP mask setting, presence of DGPS
corrections, etc. If the default or current software setting requires that a factor is met, then if
that factor is not met the solution will be marked as invalid.

2. SiRF Technology Inc. does not support magnetic declination. All “course over ground” data

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High Performance GPS Engine Board

are geodetic WGS84 directions relative to true North.

VTG - Course Over Ground and Ground Speed

Note – Fields marked in italic red apply only to NMEA version 2.3 (and later) in this NMEA

message description

Table A-7 contains the values for the following example:

$GPVTG,309.62,T,,M,0.13,N,0.2,K,A*23

Table A-7 RMC Data Format

Name Example Units Description

Message ID $GPVTG VTG protocol header
Course 309.62 degrees Measured heading
Reference T True
Course degrees Measured heading
Reference M Magnetic1
Speed 0.13 knots Measured horizontal speed
Units N Knots
Speed 0.2 Km/hr Measured horizontal speed
Units K Kilometers per hour

Mode A A=Autonomous, D=DGPS, E=DR

N=Output Data Not Valid

Checksum *23
<CR><LF> End of message termination

SiRF Technology Inc. does not support magnetic declination. All “course over ground” data are
geodetic WGS84 directions.

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NMEA Input Command

A). Set Serial Port ID: 100 Set PORTA parameters and protocol

This command message is used to set the protocol (SiRF Binary or NMEA) and/or the
communication parameters (baud rate, data bits, stop bits, and parity). Generally, this command
is used to switch the module back to SiRF Binary protocol mode where a more extensive
command message set is available. When a valid message is received, the parameters are stored
in battery-backed SRAM and the receiver will resumes using the saved parameters.

Table B-1 contains the input values for the following example:
Switch to SiRF binary protocol at 9600,8,N,1

$PSRF100,0,9600,8,1,0*0C

Table B-1 Set serial Port Data Format

Name Example Units Description
Message ID $PSRF100 PSRF100 protocol header
Protocal 0 0=SiRF Binary, 1=NMEA
Baud 9600 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
DataBits 8 8,7. Note that SiRF protocol is only valid for 8 Data bits
StopBits 1 0,1
Parity 0 0=None, 1=Odd, 2=Even
Checksum *0C
<CR><LF> End of message termination

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B). Navigation lnitialization ID：101 Parameters required for start

This command is used to cause a restart of the receiver, and to specify the type of restart.
Optionally, it may also initialize position (in X, Y, Z ECEF coordinates), clock drift, GPS Time Of
Week and GPS Week Number. This enables the receiver to search for the correct satellite signals
at the correct signal parameters. Correct initialization parameters enable the receiver to quickly
acquire signals.
For software that does not support initializing data (GSW3, GSWLT3, SiRFXTrac), attempting to
include initializing data may cause unpredictable results. Do not set the initialize-data bit in the
ResetCfg word.

Table B-2 contains the input values for the following example:
Start using known position and time.

$PSRF101,-2686700,-4304200,3851624,96000,497260,921,12,3*1C

Name Example Units Description
Message ID PSRF101 PSRF101 protocol header
ECEF X -2686700 Meters X coordinate position
ECEF Y -4304200 Meters Y coordinate position
ECEF Z 3851624 Meters Z coordinate position
clkDrift 96000 Hz

Clock offset of the receiver in Hz☆

TimeOfWeek 497260 Sec GPS Time Of Week
WeekNo 921

GPS Week Number
（ Week No and Time Of Week calculation from
UTC time）

ChannelCount 12

Number of channels to use.1-12. If your CPU
throughput is not high enough, you could decrease
needed throughput by reducing the number of active

channels
ResetCfg 3 See Table B-3 & B-4
Checksum *1C
<CR><LF> End of message termination

☆Use 0 for last saved value if available. If this is unavailable, a default value of 75000 for GSP1,
95000 for GSP 1/LX will be used.

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Table B-3 Reset Configuration Bit Map

Bit Description

0☆

Data valid flag: 1 = Use data in ECEF X, Y, Z, Clock Offset, Time of Week and Week

number to initialize the receiver; 0 = Ignore data fields
1 Clear ephemeris from memory: blocks Snap or Hot Start from occurring
2 Clear all history (except clock drift) from memory: blocks Snap, Hot, and Warm Starts

Factory Reset: clears all GPS memory including clock drift. Also clears almanac stored
3

in flash memory
4

Enable Nav Lib data (YES = 1, NO = 0) ★

☆ For software that does not support initialized data (GSW3, GSWLT3, SiRFXTrac) setting this

bit may cause unpredictable results. Do not attempt to use initializing data.01

★ If Nav Lib data are enabled, the resulting messages are enabled: Clock Status (Message ID 7),

50BPS (Message ID 8), Raw DGPS (Message ID 17), NL Measurement Data (Message ID 28),
DGPS Data (Message ID 29), SV State Data (Message ID 30), and NL Initialized Data
(Message ID 31). All messages sent at 1 Hz. If SiRFDemo is used to enable Nav Lib data, the
bit rate is automatically set to 57600 by SiRFDemo.2

Table B-4 Reset Configuration - SiRFLoc Specific

Decimal Description
00 Perform a hot start using internal RAM data. No initialization data is used.
01 Use initialization data and begin in start mode. Uncertainties are 5 seconds time

accuracy and 300 km position accuracy. Ephemeris data in SRAM is used.

02 No initialization data is used, ephemeris data is cleared, and warm start performed

using remaining data in RAM.

03 Initialization data is used, ephemeris data is cleared, and warm start performed using

remaining data in RAM.

04 No initialization data is used. Position, time, and ephemeris are cleared, and a cold

start is performed.

08 No initialization data is used. Internal RAM is cleared and a factory reset is performed.

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C). Set DGPS Port ID: 102 Set PORT B parameters for DGPS input

This command is used to control the serial port used to receive RTCM differential corrections.
Differential receivers may output corrections using different communication parameters. If a
DGPS receiver is used that has different communication parameters, use this command to allow
the receiver to correctly decode the data. When a valid message is received, the parameters are
stored in battery-backed SRAM and the receiver restarts using the saved parameters.

Table B-5 contains the input values for the following example:
Set DGPS Port to 9600 baud, 8 data bits, 1 stop bit, no parity bit.

$PSRF102,9600,8,1,0*12

Table B-5 Set serial Port Data Format

Name Example Units Description
Message ID $PSRF102 PSRF102 protocol header
Baud 9600 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
DataBits 8 8,7. Note that SiRF protocol is only valid for 8 Data bits
StopBits 1 0,1
Parity 0 0=None, 1=Odd, 2=Even
Checksum *12
<CR><LF> End of message termination

D). Query/Rate Control ID: 103 Query standard NMEA message and/or set output rate

This command is used to control the output of standard NMEA messages GGA, GLL, GSA, GSV,
RMC, and VTG. It also controls the ZDA message in software that supports it. Using this
command message, standard NMEA messages may be polled once, or setup for periodic output.
Checksums may also be enabled or disabled depending on the needs of the receiving program.
NMEA message settings are saved in battery-backed memory for each entry when the message
is accepted.

Table B-6 contains the input values for the following example:
Query the GGA message with checksum enabled

$PSRF103,00,01,00,01*25

Table B-6 Query/Rate Control Data Format

Name Example Unit Description
Message ID $PSRF103 PSRF103 protocol header
Msg 00 Message to control. See Table B-7

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Mode 01 0 = Set Rate, 1 = Query one time
Rate 00

Output Rate, 0 = Off, 1-255 = seconds between

sec

messages1
CksumEnable 01 0=Disable Checksum, 1=Enable Checksum
.Checksum *25
<CR> <LF> n End of message terminatio

Table B-7 Messages

Value Description

0 GGA
1 GLL
2 GSA
3 GSV
4 RMC
5 VTG
6 MSS (If internal beacon is supported)
7 Not defined
8 ZDA (if 1PPS output is supported)
9 Not defined

Note – In TricklePower mode, the update rate specifies TricklePower cycles rather than
seconds. If the TP cycle is set at 5 seconds, then an update rate of 2 means to output the
message every 2 cycles, or 10 seconds.

E). LLA Navigation lnitialization ID: 104 Parameters required to start using Lat/Lon/Alt

This command is used to cause a restart of the receiver, and to specify the type of restart.
Optionally, it may also initialize position (in lattitude, longitude, and altitude), clock drift, GPS Time
Of Week and GPS Week Number. This enables the receiver to search for the correct satellite
signals at the correct signal parameters. Correct initialization parameters enable the receiver to
quickly acquire signals.
For software that does not support initializing data (GSW3, GSWLT3, SiRFXTrac), attempting to
include initializing data may cause unpredictable results. Do not set the initialize-data bit in the
ResetCfg word..

Table B-8 contains the input values for the following example:
Start using known position and time.

$PSRF104,37.3875111,-121.97232,0,96000,237759,1946,12,1*07

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Table B-8 LLA Navigation Initialization Data Format

Name Example Unit Description
Message ID $PSRF104 PSRF104 protocol header
Lat 37.3875111 degrees Latitude + = North (Range 90 to -90)
Lon -121.97232 degrees Longitude + = East (Range 180 to -180)
Alt 0 meters Altitude position
ClkDrift 96000 Hz Clock Drift of the Receiver1
TimeOfWeek 237759 sec GPS Time Of Week
WeekNo 1946 Extended GPS Week Number
ChannelCount 12 Range 1 to 12
ResetCfg 1 See Table B-9
Checksum *07
<CR> <LF> End of message termination

Use 0 for last saved value if available. If this is unavailable, a default value of 96,250 Hz is used.

Table B-9 Reset Configuration Bit Map

Bit Description

0☆

Data valid flag: 1 = Use data in ECEF X, Y, Z, Clock Offset, Time of Week and Week

number to initialize the receiver; 0 = Ignore data fields
1 Clear ephemeris from memory: blocks Snap or Hot Start from occurring
2 Clear all history (except clock drift) from memory: blocks Snap, Hot, and Warm Starts
3 Factory Reset: clears all GPS memory including clock drift. Also clears almanac stored

in flash memory
4

Enable Nav Lib data (YES = 1, NO = 0) ★

☆ For software that does not support initialized data (GSW3, GSWLT3, SiRFXTrac) setting this

bit may cause unpredictable results. Do not attempt to use initializing data.

★ If Nav Lib data are enabled, the resulting messages are enabled: Clock Status (Message ID 7),

50BPS (Message ID 8), Raw DGPS (Message ID 17), NL Measurement Data (Message ID 28),
DGPS Data (Message ID 29), SV State Data (Message ID 30), and NL Initialized Data
(Message ID 31). All messages sent at 1 Hz. If SiRFDemo is used to enable Nav Lib data, the
bit rate is automatically set to 57600 by SiRFDemo.

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F). Development Data On/Off ID: 105 Switch Development Data Messages On/Off

This command turns development data (debug messages) on and off. Development data can be
used to help diagnose system problems since many parts of the software contain messages that
are output when problems are detected.

Table B-10 contains the input values for the following example:

$PSRF105,1*3E

Table B-10 Development Data On/Off Data Format

Name Example Unit Description
Message ID $PSRF105 PSRF105 protocol header
Debug 1 0=Off, 1=On
Checksum *3E
<CR> <LF> End of message termination

G). Select Datum ID: 106 Selection of datum to be used for coordinate Transformations

This message allows the selection of an alternate map datum. The receiver software may contain
one or more alternate datums in addition to WGS84, the default GPS datum. The table below lists
some datums that may be in a particular software build. In addition, other datums may have been
added by either SiRF or by developers with SDK software access. Avaliable datums, if different
from the list below, should be documented in the system or software documentation.

Table B-11 contains the input values for the following examples:

1. Datum select TOKYO_MEAN

$PSRF106,178*32

Table B-11 Select Datum Data Format

Name Example Unit Description
Message ID $PSRF106 PSRF106 protocol header
Datum 178 21=WGS84

178=TOKYO_MEAN
179=TOKYO_JAPAN
180=TOKYO_KOREA

181=TOKYO_OKINAWA
Checksum *32
<CR> <LF> End of message termination

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PCB Layout Recommend

Recommended Layout PAD

Unit: mm
Tolerance:

0.1mm

PCB Layout Recommendations

Do not routing the other signal or power trace under the engine board.

RF:

This pin receives signal of GPS analog via external active antenna .It has to be a controlled
impedance trace at 50ohm.
Do not place the RF traces close to the other signal path and not routing it on the top layer.
Keep the RF traces as short as possible.

Antenna:

Keep the active antenna on the top of your system and confirm the antenna radiation pattern、
axial ratio、power gain、noise figure、VSWR are correct when you Setup the antenna in your case.

2010/4/1

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ET-314AC
High Performance GPS Engine Board

Recommended Reflow Profile:

Pre heating temperature:
Heating temperature:

150±10[℃]
235±5[℃]

Pre heating time: 90±30[sec.]
Heating time: 10±1[sec.]

2010/4/1

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