View source for OctoClock CDA-2990

== Device Overview ==
The OctoClock is an affordable solution for high-accuracy time and frequency reference distribution.  The OctoClock accepts 10 MHz and PPS signals from an external source, and distributed each signal 8 ways.  This is a useful accessory for users that would like to build multi-channel systems that are synchronized  to a common timing source. 

== Key Features==
{|
|style="vertical-align:top"|
*8-Way Time and Frequency Distribution (1 PPS and 10 MHz)
*Convenient Solution for Multi-Channel Synchronization
*Use with MIMO Capable N-Series Devices for Coherent System
*External 10 MHz/1 PPS Source Required
*19" Rackmount – 1U
|[[File:Product octoclock.jpg|250px|center]] 
|}

==Signal Levels==
; 10 MHz output : 1.25 Vpp at 50 ohms, 3.3Vpp at 1M ohms
; 1 PPS output: 20% duty cycle square wave with amplitude 5 V

; 10 MHz input : 0-20 dBm
; 1 PPS input: 2.5-5 V

==Physical Specifications==
===Dimension (1U Rackmount)===
4 x 17.187x 1.75 inches

==Environmental Specifications==
===Operating Temperature Range===
* 0-40 °C

===Operating Humidity Range===
* 10% to 90% non-condensing

==Schematics==
===OctoClock===
[http://files.ettus.com/schematics/octoclock/octoclock.pdf OctoClock Schematics]

==Key Component Datasheets==
{| class="wikitable" style="width:80%"
!Part Number
!Description
!Schematic ID (Page)
|-
|[http://ww1.microchip.com/downloads/en/DeviceDoc/39662e.pdf ENC28J60−DIG]
|Ethernet Controller
|U103 (1)
|-

|[http://www.atmel.com/images/doc2467.pdf ATmega128]
|Microcontroller
|U102 (1)
|-

|[http://www.mymectronic.com/datasheet/13059_4168782_m9107.pdf M9107]
|SMT OCXO-Based GPSDO
|U206 (2)
|-

|[http://www.ti.com.cn/cn/lit/ds/symlink/sn74aup1t57.pdf SN74AUP1T57]
|VOLTAGE-LEVEL TRANSLATOR
|U204, U203 (2)
|-

|[http://www.ti.com/lit/ds/symlink/cdce18005.pdf CDCE18005−PWR]
|Output Clock Programmable Buffer
|U205 (2)
|-

|[http://www.nxp.com/documents/data_sheet/74HC_HCT4020.pdf 74HC4020]
|Binary Ripple Counter
|U207 (2)
|-

|[http://www.ti.com/lit/ds/symlink/lmz12001.pdf LMZ12001]
|Power Module
|U101 (1)
|-
|}

==Mechanical Info==
===Weight===
2.6 lbs

===Drawings===
* [[File:cu ettus octoclock cca.pdf]]
* [[File:cu ettus-octoclock.pdf]]

==Certifications==
===RoHS===
As of December 1st, 2010 all Ettus Research products are RoHS compliant unless otherwise noted. More information can be found at [http://ettus.com/legal/rohs-information http://ettus.com/legal/rohs-information]

===China RoHS=== 
'''Management Methods for Controlling Pollution Caused by Electronic Information Products Regulation'''

'''Chinese Customers''' 

National Instruments is in compliance with the Chinese policy on the Restriction of Hazardous Substances (RoHS) used in Electronic Information Products. For more information about the National Instruments China RoHS compliance, visit [http://www.ni.com/environment/rohs_china ni.com/environment/rohs_china].

==Certificate of Volatility==
===OctoClock===
* [[Media:OctoClock CoV.pdf]]

==Firmware==
The OctoClock's firmware is divided into two image files: octoclock_bootloader.hex and octoclock_r4_fw.hex. All image files can be found [http://files.ettus.com/binaries/images/ here], in version-specific ZIP files. Download the version corresponding to the version of UHD that you're running. You must use at least version 3.9.2.

* Full instructions on updating the OctoClock's firmware is located here: http://files.ettus.com/manual/page_octoclock.html#upgrading_device
* Source of the firmware for the OctoClock is located at: https://github.com/EttusResearch/uhd/tree/master/firmware/octoclock

==Downloads==
[https://www.ettus.com/content/files/OctoClock_Spec_Sheet.pdf OctoClock Spec Sheet]

[http://files.ettus.com/manual/md_fpga.html FPGA Resources]

[http://files.ettus.com/binaries/uhd_stable/ UHD Stable Binaries]

[https://github.com/EttusResearch/uhd UHD Source Code on Github]



==FAQ==
*'''What is the OctoClock'''

The OctoClock is a USRP-compatible accessory that allows you to easily synchronize up to 8 USRP radios. Multiple OctoClock devices can be combined for synchronization of larger numbers of USRP radios.

*'''When would I used the OctoClock'''

The OctoClock is useful for synchronizing multiple USRP devices for high channel count systems.

The following applications can benefit from OctoClock clock distribution:

*Direction Finding
*Beamforming
*Adaptive Beamforming
*Multiple-In-Multiple-Out (MIMO) Prototyping
*Geolocation Systems that Use Time-Difference-of-Arrival (TDOA)
*Multi-Channel, Multi-Static, and Passive RADAR
*Multi-Band GPS Record and Playback
*Multi-Band Cellular Monitoring

Essentially, anything that requires from synchronization or the distribution of timing information would benefit from the use of the OctoClock.

*'''Are there example applications that could benefit from the OctoClock'''

32-Channel Phased-Array Receiver Built with QR210 - OctoClock a Component in the System

Afford 8x8 MIMO Testbed

Share your applications with us and we will add them to the list.

*'''How does the OctoClock work'''

The OctoClock accepts 10 MHz and PPS signals from an external source. Active circuits are used to amplify and split the signals 8-ways. Matched-length traces minimize phase differences between all 10 MHz and 1 PPS outputs

The OctoClock-G includes an internal GPSDO (GPS Disciplined Oscillator) which provides an internal source for 10 MHz and PPS from an OCXO high precision oscillator.  Add a GPS antenna  (optional) with a clear view of the sky for GPS Disciplining of the OCXO that futher enhances frequency accuracy of the OCXO and global time synchronization.

*'''Where can I find user manuals for the OctoClock and USRP'''

Here is helpful document. Sync. and MIMO w/ the USRP

Also, here is some documentation on how to use UHD™ to interact with multi-USRP systems.

*'''What USRP model do you recommend for MIMO systems'''

The USRP N200 or N210 and USRP X300 or X310 are recommended for building high channel count and MIMO systems. These models provide external PPS and 10 MHz reference inputs.  The USRP N200 and N210 support the USRP MIMO cable.

The USRP B100, B200, B210, E100, E110, and E310 can be synchronized with 10 MHz/PPS but are not phase coherent MIMO capable devices. The USRP1 cannot be synchronized with 10 MHz/PPS.

*'''How does the automatic switchover functionality work'''

When using the OctoClock-G, the Internal/External switch on the front panel allows the user to choose between the  internal GPSDO and external source 10 MHz/PPS source.  If the selected sournce is not availble, the device will automatically switch over to the backup frequency source.  When switchover is active the corresponding LED indicator will illuminate.

If neither source is present, the internal, external and status LEDs will not be illuminated and the user will not received valid 10 MHz/PPS outputs.

*'''What do the LED indications mean'''

The following list describes the behavior when each of the 6  LED status indicators is illuminated:

*Internal - internal GPSDO is selected and present.
*External - external source is selected and present
*Status - Either the internal GPSDO or external source is selected. If neither source is present this LED will turn off (no signals are output).
*PPS - selected PPS pulse high.
*GPS Locked - GPS is receiving signals and has valid time/position lock.
*Power - Power is applied - smoke is still inside.

*'''What are the input and output specifications'''

*10 MHz Input – 0-10 dBm
*10 MHz Outputs - ~1.4 Vpp Square Wave, Impedance 50 ohm nominal
*1 PPS Input - Logic-level pulse, 2.5V - 5V
*1 PPS Outputs - Logic-level pulse, 2.5V - 5V

*'''What is the function of the Ethernet port'''

Currently, the Ethernet port is non-functional. In the future the Ethernet port may be used to provide a method for reading GPS time and NMEA sentences.

*'''What is the input voltage rating'''

The OctoClock can be powered at any voltage between 6 and 15Vdc.

*'''Are the design files open source'''

As with all of our products, the driver code is free & open source, and can be found in our UHD repository. The schematics are also available.


[[Category:Hardware Resources]]