Novus N4430-O-G User manual

Users manual
N4430-O-G
Revision #:
B
Date:
8-23-18
Page 1of 74
NR4430-O-G
GNSS Locked Reference with OCXO Holdover / AutoCal
All information provided herein is the property of Novus Power Products L.L.C. The
information included may be reproduced without the permission or prior approval of Novus
Power Products L.L.C. for the purpose of operating the equipment.

Users manual
N4430-O-G
Revision #:
B
Date:
8-23-18
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Contents
1.0 Summary ..................................................................................................................... 4
1.1 Dimensions........................................................................................................................................5
1.2 Input/Output/Indicators ............................................................................................ 6
2.0 Controls and Indicators ............................................................................................... 7
2.1 GNSS Lock LED..................................................................................................................................7
2.2 Satellite Number Counter LED.............................................................................................................7
2.3 Status Good Signal (CMOS 3V3 Active High) ........................................................................................7
2.4 UART TX/RX ......................................................................................................................................7
2.5 Power connector detail .......................................................................................................................8
3.0 Inputs / Outputs ......................................................................................................... 8
3.1 GNSS Antenna (MCX) .........................................................................................................................9
3.2 PPS 1 / PPS 2 (MMCX)......................................................................................................................10
3.4 10MHz Sine .....................................................................................................................................12
3.5 Serial/UART/NMEA ...........................................................................................................................12
4.0 Typical Phase Noise ................................................................................................... 12
5.0 Built-in Test............................................................................................................... 13
6.0 Power ........................................................................................................................ 13
7.0 GNSS Function........................................................................................................... 13
8.0 Mechanical................................................................................................................. 15
9.0 Communication Specification .................................................................................... 16
Serial data output timing △4............................................................................................ 17
NMEA Sentence Format ................................................................................................... 18
Proprietary Sentence Format: ......................................................................................... 19
Standard NMEA Output Sentences .................................................................................. 20
GGA –Global Positioning System Fix Data Format: ..................................................................................21
GLL –Geographic Position - Latitude/Longitude △6................................................................................22
GNS –GNSS Fix Data Format: ................................................................................................................23
GSA –GNSS DOP and Active Satellites △4.............................................................................................25
GSV –GNSS Satellites in View △4 ...........................................................................................................26
RMC –Recommended Minimum Navigation Information△6 .......................................................................28
VTG –Course Over Ground and Ground Speed Format: ...........................................................................30
ZDA –Time & Date Format: ...................................................................................................................30
Proprietary NMEA Input Sentences ................................................................................. 31
GNSS –Satellite System Configuration △4△8 ...........................................................................................32
FIXMASK –Setting of Positioning and Satellite Mask △4 ...........................................................................34
PPS –Setting of PPS（Pulse per second）△4 Format: ..............................................................................36

Users manual
N4430-O-G
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Date:
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RESTART - Restart command △4 Format:................................................................................................38
TIME –Setting of time information △4 ....................................................................................................39
TIMEZONE –Local Zone Time △4 ...........................................................................................................41
SURVEY –Position Mode △1 Format:.......................................................................................................42
FREQ –Setting of GCLK FREQUENCY △2△7 Format:.................................................................................46
DEFLS –Setting of default leap second △4 △6 Format:.............................................................................47
TIMEALIGN –setting of time alignment △4 Format: .................................................................................48
Restriction: ...........................................................................................................................................49
FLASHBACKUP –Setting of backup in Flash △4 Format: ...........................................................................50
CROUT –Setting of CR Output Format:...................................................................................................51
CFG –Setting of Application Software............................................................................. 52
NMEAOUT –Standard NMEA Output △9 ..................................................................................................52
UART1 –Serial Communication Port Format: ...........................................................................................52
SYS –PVT System .................................................................................................................................54
GPIO –General Purpose Input/output Format: ........................................................................................54
Proprietary NMEA Output Sentences............................................................................... 55
ACK –Output the Command Reception Check Format:.............................................................................55
CR –eRide GNSS Core Library Interface ......................................................................... 56
CRW(TPS1) –Output Time Transfer Info per Second (Date and leap second) △4△5 Format:.......................56
CRX(TPS2) –Output Time Transfer Info per Second (PPS) △4 Format:......................................................59
CRY(TPS3) –Output Time Transfer Info per Second (Survey & TRAIM) Format: ........................................61
CRZ (TPS4) –Output Time Transfer Info per Second (FREQUENCY) △3 Format: ........................................63
CRM –Measurement Data of GPS ...........................................................................................................65
CRN –Navigation Data...........................................................................................................................66
SYS –Answer of PVT System .................................................................................................................67
GPIO- General Purpose Input/output Format: ..........................................................................................67
FIXSESSION- Fix Session △1 Format: ......................................................................................................68
ANTSEL- Antenna selecting △1 Format: ...................................................................................................68
BBRAM - Battery Backup Random Access Memory △1 Format: ..................................................................69
MSG –Event Driven Message △1 Format:................................................................................................69
Backup of the Receiver Parameters (for BBRAM) △4 ....................................................... 70
Technical Specification.................................................................................................... 72

Users manual
N4430-O-G
Revision #:
B
Date:
8-23-18
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1.0 Summary
The NR4430-GNSS is a GNSS locked 10 MHz Frequency Reference with auto-
calibration.
Compact GNSS locked reference designed to be easily integrated into your system
to provide precision 10 MHz, PPS and NMEA for master timing. The unit features a
26 channel high-sensitivity, high-accuracy Multi-GNSS receiver. Supports TRAIM,
GPS, GLONASS, QZSS, SBAS, Active Anti-Jamming and Advanced Multipath
Mitigation Functions. Digital control loop provides low close in phase noise and
pulse to pulse jitter on the PPS of less than 1 ns. Auto-calibration stores the most
recent compensation coefficients dramatically minimizing long-term drift. A single 5
Vdc power supply simplifies system integration. Status signals alert the system to
BIT failures or loss of GNSS signal.
The signal source is a GNSS disciplined OCXO, actively controlled by complex
algorithm designed to minimize frequency error and PPS jitter. The 10 MHz sine
output is sourced from an intrinsically low jitter voltage-controlled crystal oscillator.
The calibration feature continually monitors the correction coefficients developed
through GNSS timing information. These are sampled multiple times per day and
stored in non-volatile memory and in the event of a GNSS loss, the saved
coefficients are applied to the OCXO. This effectively eliminates long-term crystal
drift.
There is an extensive built-in test loop that drives two LEDs and a single buffered
status bit signal from the 10-pin connector offering the ability to remotely monitor for
fault or loss of GNSS lock. There is also a GNSS lock status signal (and LED), PPS
and a serial port to provide access to NMEA time stamp data.
All inputs and outputs are electrostatic discharge protected. Any output can be
shorted indefinitely with no permanent damage to the unit.

Users manual
N4430-O-G
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Date:
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1.1 Dimensions
Con 14 is a 10 pin header (unpopulated) with 0.100” spacing:
- Pin 1 at x=2951 mils, y=1152 mils.
- Pin 10 at x=3047 mils, y = 750 mils

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1.2 Input/Output/Indicators
1
10MHz Sine Out (MCX) 1Vrms
2
PPS 1 Out (MMCX) 3V3 CMOS
3
PPS 2 Out (MMCX) 3V3 CMOS
4
Satellited LED
5
Antenna Input (MMCX)
6
Lock LED
7
Power/Alert/UART/PPS
8
Power 5Vdc

Users manual
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2.0 Controls and Indicators
2.1 GNSS Lock LED
This is normally green when GNSS locked and the loop is locked. The LED
flashes green twice when the GPS is not locked, once when the GPS is locked,
and the loop is in warmup / tracking.
2.2 Satellite Number Counter LED
This LED flashes the number of satellites currently acquired. If the unit will not
lock or takes a long-time to lock - monitoring this LED could help troubleshoot
the problem. If only a few satellites can be acquired, the antenna may need to
be confirmed to make sure it has a clear view of the sky.
2.3 Status Good Signal (CMOS 3V3 Active High)
The status signal is available from the power/serial 10-pin connector. A logic
level low indicates the unit has failed self-test. Logic high (3V3) indicates
passed self test.
2.4 UART TX/RX
The UART TX/RX provides NMEA 0183 strings as well as proprietary status
strings, which allow monitoring of the health, performance and frequency
measurement of the unit. The format is serial 3V3, with default baudrate of
38400, 1 stop bit, no parity.

Users manual
N4430-O-G
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Date:
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2.5 Power connector detail
1
Optional PPS (CMOS)
2
UART TX (CMOS)
3
GND
4
Alert (CMOS)
5
GND
6
N/C
7
UART RX (CMOS)
8
5Vdc
9
5Vdc
10
GND
3.0 Inputs / Outputs
Each 10MHz or PPS output is fault and electrostatic discharge protected. Each
output is independent and any output can be faulted for an indefinite period of time
with no permanent damage.

Users manual
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3.1 GNSS Antenna (MCX)
MCX connects to the GNSS ant - provides 3.5VDC/45ma max.
Antenna specifications should meet the following characteristics:
Operating Frequency: 1575.42 MHz, +/-2 MHz
Input Impedances: 50 Ohm
VSWR: 1.5 (typical)
Bandwidth: 25 MHz (typical) +/- 3dB points
Polarization: Right Hand Circular
Power Requirements: 5 +/- 0.25 VDC
Power Consumption: 26mA @ 5 VDC (typical)
Novus NA103 Novus NA106

Users manual
N4430-O-G
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Date:
8-23-18
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3.2 PPS 1 / PPS 2 (MMCX)
MMCX - one pulse per second - 3.3 VDC CMOS - PPS can also be made available
on pin 1 of the power/serial connector.
There are two PPS signals available- Radio PPS and Synthesized PPS. The radio
PPS comes directly from the GNSS receiver. It is accurate to 1 sigma at 15 ns. It
has a jitter level that is on the order of 6 ns pulse to pulse. The Synthesized PPS is
derived from the crystal and has a pulse to pulse jitter level of below 1 ns after 30
mins at stable temperature.
The control loop modulates the OCXO to keep the Synthesized PPS to within 50 ns
of the Radio PPS. There are commands sent thru the serial port that allow the user
to configure the PPS output. The default output is synthesized PPS, disciplined to
the GNSS PPS. Selecting between GNSS PPS or Synthesized PPS will affect both
PPS outputs.
PPS from radio

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Stabilized PPS

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3.4 10MHz Sine
1Vrms into 50 Ohms.
3.5 Serial/UART/NMEA
Standard NMEA output NMEA-0183, and proprietary status $GPNVS at logic level
CMOS. Default baudrate is 38400, 1 stop bit, no parity.
The status $GPNVS strings follow the format defined in $GPNVS String Definitions
document available to download from the website.
4.0 Typical Phase Noise
10MHz Sine- Primary Output
Offset Frequency (Hz) Typical (dBc / Hz)
10 -102
100 -110
1K -140
10K -145
There are optional phase noise performance levels available - contact factory.

Users manual
N4430-O-G
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B
Date:
8-23-18
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5.0 Built-in Test
There are a number of power supplies in the design to meet special needs and
noise reduction. Each supply is monitored and a power failure will be indicated by
the status pin dropping to 0V. The NMEA output $GPNVS can also be monitored
for power supply +/-5V, Antenna current, Output Vrms, etc.
6.0 Power
The standard unit is designed to operate from a nominal 5 VDC ±0.1 volts. During
turn on, the OCXO draws considerable current and the maximum current will
approach 1000ma. After the OCXO has stabilized, the current will be in the 200 to
500ma range depending upon temperature. Any noise on the power supply will
compromise phase noise performance. The power should be heavily filtered and
decoupled at the connector.
7.0 GNSS Function
The receiver needs to be able to see at least four satellite vehicles (SVs) to obtain
an accurate 3-D position fix. When travelling in a valley or built-up area, or under
heavy tree cover, you will experience difficulty acquiring and maintaining a coherent
satellite lock. Complete satellite lock may be lost or only enough satellites (3)
tracked to be able to compute a 2-D position fix, or a poor 3-D fix due to insufficient
satellite geometry (i.e. poor DOP). Inside a building or beneath a bridge, it may not
be possible to update a position fix. The receiver can operate in 2-D mode if it goes
down to seeing only 3 satellites by assuming its height remains constant. But this
assumption can lead to very large errors, especially when a change in height does
occur. A 2-D position fix is not considered a good or accurate fix; it is simply “better
than nothing”.
The receiver’s antenna must have a clear view of the sky to acquire satellite lock.
Remember, it is the location of the antenna that will be given as the position fix. If
the antenna is mounted on a vehicle, survey pole or backpack, allowance for this
must be made when using the solution.

Users manual
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To measure the range from the satellite to the receiver, two criteria are required:
signal transmission time and signal reception time. All GNSS satellites have several
atomic clocks that keep precise time and are used to time-tag the message (i.e.
code the transmission time onto the signal) and to control the transmission
sequence of the coded signal. The receiver has an internal clock to precisely
identify the arrival time of the signal. Transit speed of the signal is a known constant
(the speed of light), therefore: time x speed of light = distance.
Once the receiver calculates the range to a satellite, it knows that it lies somewhere
on an imaginary sphere whose radius is equal to this range. If a second satellite is
then found, a second sphere can again be calculated from this range information.
The receiver will now know that it lies somewhere on the circle of points produced
where these two spheres intersect.
When a third satellite is detected and a range determined, a third sphere intersects
the area formed by the other two. This intersection occurs at just two points. A
fourth satellite is then used to synchronize the receiver clock to the satellite clocks.
In practice, just four satellite measurements are sufficient for the receiver to
determine a position, as one of the two points will be totally unreasonable (possibly
many kilometers out into space). This assumes the satellite and receiver timing to
be identical. In reality, when the receiver compares the incoming signal with its own
internal copy of the code and clock, the two will no longer be synchronized. Timing
error in the satellite clocks, the receiver, and other anomalies, mean that the
measurement of the signal transit time is in error. This, effectively, is a constant for
all satellites since each measurement is made simultaneously on parallel tracking
channels. Because of this, the resulting ranges calculated are known as “pseudo-
ranges”.
To overcome these errors, the receiver then matches or “skews” its own code to
become synchronous with the satellite signal. This is repeated for all satellites in
turn, thus measuring the relative transit times of individual signals. By accurately
knowing all satellite positions, and measuring the signal transit times, the user’s
position can be accurately determined.
This LED illuminates green when the unit is locked to the GNSS system. If the LED
is flashing green, the unit is operating on the OCXO and is attempting to gain GNSS
Lock.
.
The GNSS lock status is also available from monitoring serial NMEA/status on the
power/serial 10-pin connector.
If the GNSS indicator remains flashing green for an extended period of time, it could
be an indication of an antenna, cabling or unit malfunction. Confirm the antenna is
still connected and has not become obstructed from a clear view of the sky. To

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check the unit, an alternate antenna can be tried in order to isolate the malfunction.
For further support, please contact the factory at 866-313-9401.
There is free software that can be downloaded from www.synreference.com that will
allow baud rate changes, cable compensation and other features (see screen
shots).
8.0 Mechanical
There are (4) 0.256”pads on the board intended for mechanical mounting. The
pads are connected to ground.

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9.0 Communication Specification
Signal Lines used: TXD, RXD
Flow Control: None
System: Full Duplex Asynchronous
Speed: Configurable, Default 38400 bps (*1)
Start Bit: 1 bit
Data Length: 8 bits
Stop Bit: 1 bit
Parity Bit: None
Data Output Interval: 1 second
Character Codes used: NMEA-0183 Ver.4.10 data based ASCII
code (*2) Protocol: Input data
NMEA Standard
sentence NMEA
Proprietary sentence
Output data
NMEA Standard
sentence NMEA
Proprietary sentence
Note 1:Communication speed can be changed into 4800, 9600, 19200, 38400, 57600
or 115200 bps.
Please refer to section “UART1 – Serial Communication Port” for how to
configurethe communication speed. In case of using low baud rate, please
adjust size of output sentence by NMEAOUT command and CROUT command
to output all sentence within onesecond.
Note 2: ”NMEA 0183 STANDARD FOR INTERFACING MARINE ELECTRONIC
DEVICES Version4.10” (NATIONAL MARINE ELECTRONICS ASSOCIATION,
June,2012)

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Serial data output timing △4
The output timing of serial data is synchronous with PPS output timing. Serial data starts
in the 25ms to 75ms range after PPS pulse occurs.t. The time in the serial data indicates
next PPS leading edge.
PPS(t-1) PPS(t) PPS(t+1)

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NMEA Sentence Format
13.1 Standard Sentence
Format:
5 bytes
Field
Description
$
Start-of Sentence marker
<address field>
5-byte fixed length. First 2 bytes represent a talker ID, and the
remaining 3 bytes do a sentence formatter.
All output sentences must begin with a “$” followed by a TalkerID.
The relevant Talker IDs are GP for GPS, GN for GNSS, GL for
GLONASS and GA for Galileo.
For the sentences received from external equipment, the GT-87
accepts any talker ID. Talker ID “XX” found on the succeeding pages
is a wildcard meaning “any valid talker ID”.
<data field>
Variable or fixed-length fields preceded by delimiter “,”(comma).
Comma(s) are required even when valid field data are not available
i.e. null fields. Ex. “,,,,,”
In a numeric field with fixed field length, fill unused leading digits
with zeroes.
*<checksum field>
8 bits data between “$” and “*” (excluding “$” and “*”) are XORed,
and the resultant value is converted to 2bytes of hexadecimal
letters. Note that two hexadecimal letters must be preceded by“*”,
and delimiter “,” is not required before *<checksum>.
All output sentences have checksum.
For input sentences, the resultant value is checked and if it is not
correct, the sentence is treated invalid.
<CR><LF>
End-of-Sentence marker
$
<address field>
,
<data field>
…
*<checksum field>
<CR>
<LF>

Users manual
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Proprietary Sentence Format:
3 bytes 3 bytes
Field
Description
$
Start-of-Sentence marker
P
Proprietary sentence identifier
<maker ID>
3-byte fixed length.
GT-87’s maker ID is “ERD” meaning eRide.
<sentence type>
Indicates the type of sentence.
<data field>
Variable or fixed-length fields preceded by delimiter
“,”(comma).
(Layout is maker-definable.)
<checksum field>
8 bits data between “$” and “*”(excluding “$” and “*”) are
XORed, and the resultant value is converted to 2 bytes of
hexadecimal letters. Note that two hexadecimal letters must be
preceded by “*”, and delimiter “,” is not required before
*<checksum>.
All output sentences have checksum.
For input sentences, the resultant value is checked and if it is
not correct, the sentence is treated invalid.
<CR><LF>
End-of-Sentence marker
$
P
<maker ID>
<sentence type>
,
<data field>
…
*<checksum field>
<CR>
<LF>

Users manual
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Date:
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Standard NMEA Output Sentences
The receiver supports eight standard NMEA output sentences (GGA, GLL, GNS, GSA, GSV,
RMC, VTG and ZDA) per NMEA standard 0183 Version 4.10 (June,2012).
By default, the RMC, GNS, GSA, ZDA, GSV and TPS sentences will be output every
second.The sentences can be independently enabled and disabled using the
$PERDCFG,NMEAOUTand/or
$PERDAPI,CROUT command described later in this document, as well as use differing
transmission rates.
The NMEA sentence descriptions in this sentence are for reference only. The sentence
formatsare defined exclusively by the copyrighted document fromNMEA.
eRide does populate all the fields described in the NMEA specification. Uncalculated fields
are indicated as “Not Supported”.