Novus NR3700-G-PPS User manual

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
Page #:
1 of 20
www.novuspower.com
NR3700-G-PPS
NMEA-PPS Source
All information provided herein is the property of Novus Power Products LLC. The
information included may be reproduced without the permission of Novus Power
Products LLC. for the purpose of operating the Novus equipment.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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Contents
1.0 Overview................................................................................................................... 3
4.0 Input/Output Connectors/Mechanical.................................................................... 15
6.0 Alerts-Function..................................................................................................... 17
9.0 Technical Specification.......................................................................................... 18
10.0 Environmental and Mechanical ............................................................................ 18
Appendix: GNSS Command Reference........................................................................ 20

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NR3700-G-
PPS
REVISION NUMBER
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DATE
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1.0 Overview
GNSS Receiver
Self Test
PPS
3.3 or 5 V CMOS
NMEA Data
Alert
GPS Lock
Power Supply
AC Adapter
DC input to +-60vdc
The NR3700-G-PPS is a GNSS locked PPS/NMEA source. Ideal for critical
timing applications. The NMEA data is configurable as to the NMEA strings to be
provided. PPS cable compensation is also possible through the RS232 port. The
PPS can be supplied at either 3.3 or 5 Vdc CMOS.
The RS232 interface provides access to the NMEA-0183 data from the GPS at a
baud rate of 38.4K. The baud rate can be changed through the RS232 port.
The unit operates from power in the voltage range of -60 to +60 VDC in three
power supply ranges that must be specified at purchase. There is also an AC
power adapter available.
PPS pulse is a LVCMOS signal and is also short and transient protected. The
PPS has an accuracy of 30 ns rms and is available on the front panel as an
option with a SMA connector
The NR3700-G-PPS also incorporates built-in test to monitor critical parameters
such as the power supplies and other functions. The built-in test drives a front
panel indicator.
The GNSS lock status is provided by a front panel indicator. An unlocked state
can be detected via the RS232 port. Many systems will use this signal to detect

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
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a long-term GNSS loss of lock state which may be caused by an antenna or
cabling issue.
Less than 5 Watts of power from a 12 VDC nominal source is consumed. An AC
power adapter is available to allow direct operation from standard AC power.
Also, Novus offers related NR3700 products that can operate anywhere from –
60 to +60 VDC. Contact the factory for further details. There is a PCB assembly
version of this product (NR4400) which offers essentially the same functionality
and can be directly embedded in a system - smaller size and lower cost.
The output is transient and fault protected.
GNSS Receiver
Sensitivity
GPS
Tracking: -161 dBm
Hot Start: -161 dBm
Warm Start: -147 dBm
Cold Start: -147 dBm
Reacquisition: -161 dBm
GLONASS
Tracking: -157 dBm
Hot Start: -157 dBm
Warm Start: -143 dBm
Cold Start: -143 dBm
Reacquisition: -157 dBm
TTFF (Time to First Fix)
Hot Start: <5 sec (@-130 dBm)
Warm Start: 35 sec (@-130 dBm)
Cold Start: 40 sec (@-130 dBm)
・Active Anti-Jamming
・Advanced Multipath Mitigation

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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The receiver needs at least four satellite vehicles (SVs) visible 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 3D fix due
to insufficient satellite geometry (i.e. poor DOP). It may not be possible to update
a position fix inside a building or beneath a bridge. The receiver can operate in 2-
D mode if it goes down to seeing only three 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. The GNSS receiver provides power for
the LNA in the antenna. The unit was designed to provide 3.5 Vdc < 40 mA of
current.
To measure the range from the satellite to the receiver, two criteria are required:
signal transmission time and signal reception time. All GPS 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.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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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.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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Antenna
Antenna - SMA
SMA female antenna connection. Provides internal 3.3VDC power at 20mA max.
The Novus NA103 Pole Mount Antenna or the Novus NA106 Magnetic Mount
Antenna are recommended for optimal performance.
The receiver and companion elements generate the PPS and NMEA serial link.
The serial link conforms to NMEA 0183 protocol. The 26 channel high-sensitivity,
high-accuracy Multi-GNSS receiver supports TRAIM, GPS, GLONASS, QZSS,
SBAS, Active Anti-Jamming and Advanced Multipath Mitigation Functions.
Typical Antenna Specs:
Frequency Band 1574 –1607 MHz
Antenna Gain 2 dBic @ 90°
Amplifier Gain @ 3.0Vdc: 26dB (typ)
Polarization RHCP
Out-of-band Rejection >60dBc @ f0 ± 50MHz
Impedance 50Ω
VSWR 2.0 Max
DC Input 2.8V - 6V
Noise Figure <2.0dB
Power Consumption 20mA (typ)

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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PPS (Pulse Per Second)
The PPS (one Pulse Per Second) relationship with the NMEA data is shown
below:
The serial data timing is for the next rising edge of the PPS pulse.
There are a number of attributes for the PPS that can be controlled via the
RS232 port with the radio:
PPS Availability
There is a TCXO that is used to maintain the PPS in the event of GNSS loss.
The radio can be programmed to either have the PPS stop when GNSS lock
occurs or continue with the stability of the internal TCXO. The TCXO has a
stability shown below.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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For applications requiring a more stable PPS –a source such as an OCXO or
atomic reference should be considered. The PPS can also be enabled or
disabled based upon a calculated accuracy.
Cable Delays
The unit can be programmed to compensate for PPS errors due to cable length.
A compensation factor of +/-100000 ns can be used.
Pulse Width
The pulse width can be programmed from 1 to 500ms.
Factory Default Settings
PPS on when estimated accuracy is within 1 usec.
Pulse width is 200ms.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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Output Drive
The PPS pulse is a CMOS drive capable of providing 30 ma. The unit is available with
either 3.3 or 5 Vdc logic levels.
PPS Accuracy
15ns(1σ) (@-130 dBm)
50ns(1σ) (@-150 dBm)
The nominal accuracy of a PPS signal that is directly from the radio is on the
order of 25 ns rms. The signal will also have ~5 ns of jitter. The jitter is due to the
characteristics of the transmission channel - multi-path and other radio effects.
The long-term accuracy of the PPS is excellent. There are numerous reference
documents produced by NIST that define accuracy.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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For those applications where the 5 ns of jitter is unacceptable, there is a more
stable source. To solve the jitter problem, a stable oscillator is locked to the PPS
and the output of the oscillator is then counted down to 1 Hz to have a jitter level
that is dominated by the oscillator and associated electronics. Normally, a
Kalman Filter is used to discipline the oscillator and the resulting performance is
a function of the design and the quality of the oscillator. PPS jitter can be
improved from the 5 ns range to less than 60 ps.
PPS Holdover
PPS holdover is concerned with the stability of the PPS when GNSS lock is lost.
The circuitry discussed to improve jitter also improves holdover. If the oscillator is
an OCXO - then a PPS drift of 5 to 10 ppb/day is achievable (< 1ms). A Rubidium
source can be used to achieve drift rate well over an order of magnitude better
than the OCXO.
NMEA - RS232
The serial NMEA data is provided on the DB9 connector.
The baud rate for the NMEA port is selectable. Communication speed can be
changed into 4800, 9600, 19200, 38400, 57600 or 115200 bps. In case of using
low baud rate, please adjust size of output sentence by NMEAOUT command
and CROUT command to output all sentence within one second.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
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What information is sent from the radio and how often, can be selected. The
NMEA sentence format:

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
Page #:
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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,NMEAOUT and/or $PERDAPI,CROUT command
described later in this document, as well as using differing transmission rates.
The NMEA sentence descriptions throughout the document are for reference
only. The sentence formats are defined exclusively by the copyrighted document
from NMEA.
There is considerable detail available from the Novus website download page:
Receiver Control Information.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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Input/Output Connectors/Mechanical
3.5
4.0
.375
.499
.189
O.150
B
BB
.500
Front Panel
Output BNC
Alert

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
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GNSS Ant - SMA connects to the GPS ant - provides 3.3 VDC 45mA max
PPS - SMA or BNC one pulse per second
RS232 - standard NMEA output NMEA-0183
Power Connector
The power connector is a 2 pin terminal block connector that mates to (ON-Shore
Tech Part# OSTTJ0211530). Wires are installed and secured with a slotted
screwdriver.
Pin assignments

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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1. power ground
2. power positive
The unit is designed to operate from 12 VDC nominal power and is reverse
polarity protected.
Pin 1 is designated on the panel and is the far-right pin as directly viewed.
Pin
1N/C
2NMEA –Tx
3NMEA- Rx
4no connection
5GND
6N/C
7N/C
8N/C
9N/C
Contact closure occurs in the normal operating state for Alert.
Alerts-Function
There are numerous critical circuits in the unit. These are monitored and a failure
of any of these will initiate an ALERT condition. The ALERT LED will flash red.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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Technical Specification
Locked Stability
<~E-11 after 100 seconds
RS232
NMEA 0183 at full RS232 levels default is 38.4K Baud
Antenna power
3.5 Vdc < 40 ma
Receiver Sensitivity
-155dBm
PPS
15ns(1σ) (@-130 dBm)
50ns(1σ) (@-150 dBm) RMS accuracy, 3.3 volt logic(5 vdc logic
option), output impedance CMOS (±20mA)
Power Requirements
9 to 15 VDC @ 1.0 amps max (10 Watts) (Voltage range -60 to
+60 available - contact Factory.
Connectors
BNC 10 MHz output
SMA PPS 3.3 VDC CMOS
Power mate
2 pin Digikey ED10554-ND
10.0 Environmental and Mechanical
Operating Temperature
0 to 50°C non-condensing (extended temperature range available)
Storage Temperature
-40 to 70°C
Width
4.0” (exclusive of connectors)
Depth
5.0”
Height
1.5”
Weight
~16 oz.

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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LIMITED HARDWARE WARRANTY
Novus Power Products (hereinafter Novus) warrants its products to the original end user (“original
purchaser”) and warranty is not transferrable. Novus guarantees that the NOVUS hardware products that
you have purchased from NOVUS are free from defects in materials or workmanship under normal use
during the LIMITED WARRANTY PERIOD. The LIMITED WARRANTY PERIOD starts on the date of
shipment and for the period of 1 (one) year to be free from defects caused by faulty materials or poor
workmanship, provided:
(a) NOVUS is notified in writing by Buyer of such defect prior to the expiration of the warranty period, and
(b) after receiving return authorization –RMA- from NOVUS, the defective item is returned with
transportation prepaid to NOVUS, Independence, Missouri, with transportation charges prepaid by Buyer
see RMA policy in Terms and conditions, and
(c) NOVUSs’ examination of such unit shall disclose to its satisfaction that such defect(s) exist and have not
been caused by misuse, neglect, improper installation, improper storage, unauthorized modifications,
inadequate maintenance, operation outside the environmental specifications for the product, repair
alteration, or accident. NOVUS assumes no risk or liability for results of the use of products purchased from
it, including but without limiting the generality of the foregoing: (1) the use in combination with any electrical
or electronic components, circuits, systems, assemblies or any other materials or substances; (2)
unsuitability of any product for use in any circuit or assembly. Removal or tampering with tamper-proof label
on merchandise will void warranty coverage unless with the written authorization from NOVUS
(d) an evaluation fee will be charged to Buyer to cover inspection and testing costs for any item returned by
Buyer under this paragraph which is found to be within specifications and/or otherwise not the responsibility
of NOVUS under the terms and conditions of this paragraph or any other part of this Agreement..
Your dated sales or delivery receipt is your proof of the purchase date. You may be required to provide
proof of purchase as a condition of receiving warranty service. You are entitled to hardware warranty service
according to the terms and conditions of this document if a repair to your NOVUS product is required during
the limited warranty period. Our obligation at NOVUS is limited to repair or replace products which prove to
be defective.
Should Novus be unable to repair or replace the product within a reasonable amount of time, the customer’s
alternate remedy shall be a refund of the purchase price upon return of the product to Novus. The liability of
NOVUS under this warranty is limited to replacing, repairing or issuing a credit, at its option, for any such
item returned by Buyer under the terms of this warranty.
EXCLUSIONS: The above warranty shall not apply to defects resulting from improper or inadequate
maintenance by the customer, customer-supplied software or interfacing, unauthorized modification or
misuse, operation outside of the environmental specifications for the product or improper site preparation
and maintenance (if applicable). For probes, cables, antennas and accessories, the warranty period is 90
(ninety) days.
PRODUCT SPECIFICATIONS: Published specifications whether contained herein or in any other materials
or documents distributed to Buyer by Novus do not become final or binding on NOVUS until approved by
NOVUS. NOVUS expressly reserves the right to change or modify specifications at any time without prior
notice.
WARRANTY LIMITATIONS: NOVUS MAKES NO OTHER WARRANTY, EITHER EXPRESSED OR
IMPLIED, WITH RESPECT TO THIS PRODUCT. NOVUS SPECIFICALLY DISCLAIMS THE IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
IN ALL CIRCUMSTANCES NOVUS’ MAXIMUM LIABILITY IS LIMITED TO THE PURCHASE PRICE OF
THE PRODUCTS SOLD. NOVUS SHALL NOT, UNDER ANY CIRCUMSTANCES BE LIABLE UPON A
CLAIM OR ACTION IN CONTRACT, TORT, INDEMNITY OR CONTRIBUTION OR OTHER CLAIMS
RELATING TO THE PRODUCTS IT SELLS WHICH EXCEEDS THIS LIABILITY LIMIT. NOVUS SHALL
NOT BE LIABLE FOR THIRD PARTY CLAIMS FOR DAMAGES AGAINST THE CUSTOMER, OR FOR

USERS MANUAL
NR3700-G-
PPS
REVISION NUMBER
B
DATE
10/20/20
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MALFUNCTION, DELAYS, INTERRUPTION OF SERVICE, LOSS OF BUSINESS, LOSS OR DAMAGE TO
EXEMPLARY DAMAGES, WHETHER OR NOT NOVUS HAS BEEN MADE AWARE OF THE POSSIBILITY
OF SUCH CLAIMS OR DAMAGES.
LIMITATION OF REMEDIES
: REGARDLESS OF WHETHER ANY REMEDY SET FORTH HEREIN FAILS OF ITS ESSENTIAL
PURPOSE, IN NO EVENT WILL NOVUS BE LIABLE TO YOU FOR ANY SPECIAL, CONSEQUENTIAL,
INDIRECT OR SIMILAR DAMAGES, INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF
BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF DATA OR BUSINESS INFORMATION (OR
OTHER PECUNIARY LOSS) ARISING OUT OF THE USE OF OR INABILITY TO USE THE HARDWARE
SUPPLIED THEREWITH EVEN IF NOVUS OR ANYONE ELSE HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY. EXCLUDED
DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION,
LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.
EXCLUSIVE REMEDIES:
THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMERS’ SOLE AND EXCLUSIVE REMEDIES. IN
NO EVENT SHALL NOVUS BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES, WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL
THEORY.
Appendix: GNSS Command Reference