Novus NR2316-OG User manual

Users manual
NR2316-OG
Revision #:
E
Date:
5/4/18
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1 of 50
www.novuspower.com
User Manual Model NR2316-OG
16 Channel GPS Locked OCXO
Frequency Reference
All information provide herein is the proprietary property of Novus Power Products
L.L.C. The information included may be reproduced without the permission of Novus
Power Products L.L.C. with out prior approval for purpose of operating the equipment.

Users manual
NR2316-OG
Revision #:
E
Date:
5/4/18
Page #:
2 of 50
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Contents
1.0 Summary....................................................................................................................... 3
2.0 Controls and Indicators –Front Panel .......................................................................... 7
2.1 GNSS Status.............................................................................................................. 8
2.2 GNSS Detailed Status............................................................................................... 8
2.3 Channel Status .......................................................................................................... 9
2.4 Status LEDs ............................................................................................................ 10
2.5 Power Supply Status............................................................................................... 11
2.6 Alert Threshold....................................................................................................... 13
2.7 Latch Channel Values............................................................................................. 16
2.8 PPS Status............................................................................................................... 16
2.9 GPS Select .............................................................................................................. 18
2.10 Save Configuration ............................................................................................... 19
2.11 Fault Status............................................................................................................ 20
2.12 UTC Mode............................................................................................................ 21
2.13 GMT Offset........................................................................................................... 21
2.14 Power Switch........................................................................................................ 22
3.0 Rear Panel................................................................................................................... 23
3.1 Channel Ouputs - BNC........................................................................................... 23
3.2 Antenna Input A/B - SMA...................................................................................... 24
3.3 DC Input.................................................................................................................. 24
3.4 AC Input.................................................................................................................. 25
3.5 RS232 DB9 Front (NMEA/Status)......................................................................... 26
3.6 RS232 DB9 Rear (Linux Console Debug).............................................................. 27
4.0 Functional Description................................................................................................ 28
4.1 Phase Noise............................................................................................................. 29
4.2 Outputs.................................................................................................................... 30
4.3 Built in Test............................................................................................................. 30
4.4 Power Supplies........................................................................................................ 30
5.0 Crystal......................................................................................................................... 31
6.0 Calibration................................................................................................................... 36
7.0 Programming Guide (RS232 Port: Front and Rear) ................................................... 37
7.1 RS232 Commands .................................................................................................. 38
7.2 Status Byte Key....................................................................................................... 43
8.0 Technical Specification............................................................................................... 46
8.1 Performance............................................................................................................ 46
8.2 Environmental and Mechanical ...............................Error! Bookmark not defined.
9.0 LIMITED HARDWARE WARRANTY.................................................................... 48
10.0 Appendix: GNSS Command Reference.................................................................... 50

Users manual
NR2316-OG
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E
Date:
5/4/18
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1.0 Summary
The NR2316 is a 16 Channel precision GNSS/GPS locked 10MHz frequency reference.
The amplifier is a low phase noise design to preserve the integrity of the reference signal.
All outputs are transient and fault protected.
The unit features auto-calibration, which ensures the most recent OCXO compensation
coefficients are stored in non-volatile memory. The compensation values eliminate drift
due to aging and/or temperature, and are stored and applied to the OCXO during loss of
GPS lock conditions. These coefficients are updated after eight hours of continuous GPS
locked state. This effectively eliminates long-term OCXO changes.
Excellent aging characteristics are achieved through the use of intrinsically low jitter
overtone SC cut crystals in a temperature controlled oven. There are ten outputs on the
rear panel (BNC) connectors. Low phase noise is achieved by the inherent crystal
characteristics and appropriate design techniques for noise mitigation.
Units can be customized to any number of channels, can be changed to PPS output, or
can be mixed to be 8 sine + 8 PPS outputs, etc.
Typical Phase Noise performance:
Offset Frequency, Typical
Offset (Hz)
Standard (dBc/Hz)
10
-110
100
-135
1k
-145

Users manual
NR2316-OG
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The NR2316-OG delivers a low phase noise curve, which can be seen in the sample
production test below.
NR2316-OG Phase Noise Measurement

Users manual
NR2316-OG
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E
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The unit features extensive reporting via the rear panel RS232 port. Equipment
status, output voltage on each channel. By being able to monitor the output
voltage, the user can detect cabling issues that cause an impedance change and
replace cabling before it completely fails. Reporting is also easily accessible via
the front panel display.
Nominal power is global AC power, but a DC power option can be ordered that
acts as the back-up power supply. Nominally 24 vdc, this port is used for power
when AC power fails. Switching between power sources is automatic and there is
no transient power outage at the equipment level. The primary power supply is
followed by low noise linear converters assemblies.

Users manual
NR2316-OG
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Users manual
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2.0 Controls and Indicators –Front Panel
This section describes the functionality of the front panel controls and indicators.
Two buttons above the status LEDs provide navigation through the menus.
In general, the NEXT button advances through the menus to the next screen,
while the SELECT button chooses between the available values on a menu.
Menus that allow selectable adjustments are the Input Threshold, Alert Threshold,
and the Attenuation setting. To adjust these values from the front panel, hold
down both buttons for two seconds, until the value begins to flash. To leave the
menu with the new value, hold down both buttons until the value is solid.

Users manual
NR2316-OG
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2.1 GNSS Status
On power up, the NR2316-OG will display the Time and Date as well as the
current status of both GNSS receivers.
GNSS: The GNSS status indication allows the user to observe the Lock status of
the receivers, and the number of GNSS satellites in view. Before GNSS lock is
acquired, the status will be “Tracking” and the number of satellites will be shown.
When GNSS lock is acquired, the status will change to “Lock.”
Time and Date: The time zone will be UTC by default, but the hour can be offset
to the local time in the UTC Offset menu. Changes to UTC offset and Hour mode
will be reflected on this screen, but will not change the NMEA output data.
2.2 GNSS Detailed Status
The GNSS Status Menu gives the user a quick reference for the quality of the
GNSS satellite signal and length of time that each receiver has been locked.
To toggle between each receiver, press the SELECT button. The screen will
display which receiver status is being viewed.
The user can then see number of GPS satellites in view, number of GLONASS
satellites in view, and the UTC time and date that lock occurred on the selected
receiver.

Users manual
NR2316-OG
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Date:
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2.3 Channel Status
The Channel Status can be determined by reading the actual RMS value on the
output of each stage. This is compared to a threshold limit that is set by the user as
a percentage variation from a saved value. The default variation value is set at
±55% percent from the current state of the amplifier, and is user programmable in
5% increments from ±10% to ±60%.
The range of acceptable Channel Amplitude can be narrowed around a connected
balanced line, such that a Channel Status below the Alert Threshold indicates a
shorted line, while a Channel Status above the Alert Threshold window indicates
a potential disconnected cable.
The threshold value at which a channel alert is triggered can be programmed on
the Alert Threshold screen, or programmed via the RS232 port. Once set, the unit
would continue to monitor each channel and a deviation beyond the set limits
would be reported as a failure on the front panel and via RS232.
The Channel Status feature can quickly detect a cabling failure. Any change in
the load impedance will change the output voltage with respect to the divider
formed by the output impedance of the amplifier and the load impedance. Failing
cables and connectors can be detected early.
The current threshold limits are displayed in addition to the actual measured
value. These values reflect the percentage threshold defined in the Alert
Threshold settings. If the output value is too low to give a valid reading. The
display will read “LOW.”
The status is displayed on the front panel and is accessible over the RS232 serial
bus via DB9. Channel Statuses can be cycled into view or can remain on a single
channel. This feature can be accessed via the NEXT button, by advancing to the
Channel Status screen. To cycle through channels in sequence, press the
SELECT button.

Users manual
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Date:
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2.4 Status LEDs
There are three status LEDs which provide a quick indication of valid unit
operation.
Alert LED: The Alert LED will illuminate flashing red to indicate A GNSS
failure or a power supply failure. The Alert LED will not flash RED if any valid
input signal is present.
Oven LED (OCXO option only): The Oven LED will illuminate red to indicate
an Oven Failure.
Oven LED (Onboard GPS): The Oven LED will illuminate steady green if all
onboard GPS/GNSS units are locked. The LED will flash green if at least one unit
is unlocked.
Fault LED: The Fault LED will illuminate flashing red to indicate a Channel
Fault, when any single channel is outside the user defined threshold.