NFS-220 Network Ready GPS Time and Frequency Standard

The NFS-220 is a low cost precision time and frequency standard that uses GPS for use in WI-FI, Wi-Max, satellite communications, telecommunications, and military communications.  This frequency standard is the newest of Brandywine's GPS Synchronizing clocks and utilizes a high performance 16 channel receiver with automatic position-averaging that enables the best use of GPS when operating in a fixed location.  The NFS220 includes 4 low phase noise 10MHz outputs, 4 1PPS outputs with individual 600PS propagation delay compensation, IRIG, Have Quick, and NTP outputs.

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Advanced Network-Ready Time and Frequency Standard

The NFS-220 from Brandywine Communications is the most advanced network-ready time and frequency standard available using Global Positioning System (GPS).Below are some of the great features of this new frequency standard:

  • High performance GPS disciplined Time/Frequency standard
  • Ethernet Interface for management and control
  • Network Time Protocol (NTP)
  • Multiple 1PPS outputs with individual delay compensation
  • Multiple Low Phase Noise 10MHz outputs with software programmable level
  • Time Code outputs including Have Quick, IRIG A, IRIG B, IRIG E, IRIG G
  • Sync to GPS or to Have Quick/1PPS per ICD-GPS-060
  • Choice of internal disciplined TCXO, OCXO or Rubidium Oscillator

The NFS220 is fitted with an internal back up oscillator that is continuously calibrated to GPS using an advanced algorithm, providing optimal frequency control of the oscillator. This ensures that the highest time and frequency accuracy is maintained if no satellites can be tracked, and ensures an ultra stable, low noise frequency reference.

The NFS220 utilizes a high performance 16 channel GPS receiver. An automatic position-averaging feature enables the best use of GPS when operating in a fixed location.
The NFS220 is fitted with an internal back up oscillator that is continuously calibrated to GPS using an advanced algorithm, providing optimal frequency control of the oscillator. This ensures that the highest time and frequency accuracy is maintained if no satellites can be tracked, and ensures an ultra stable, low noise frequency reference.

The basic NFS220 includes a precision OCXO frequency standard, while TCXO and Rubidium oscillators are optionally available to giving a variety of price and performance options. An option with a low noise OCXO phase locked to a rubidium is also available, combining the low noise characteristic with the OCXO with the long-term stability of a rubidium.

The NFS220 provides “at a glance” status indication via front panel LED’s and can be integrated with other management systems using Ethernet and serial ports.

The NFS220 provides simple integration into military platforms by allowing synchronization from Have Quick time code, which is available on military SA-ASM GPS receivers such as the DAGR or PLGR. The NFS220 also generates Have Quick and 1PPS signals compatible with ICD-GPS-060.

The integrated Ethernet interface provides Network Time Protocol (NTP) synchronization of other connected computers.

In addition to NTP, the NFS220 Ethernet interface contains a built in web server that allows the NFS220 to be controlled using a standard web browser such as Internet Explorer. Simple Network Management Protocol (SNMP) allows easy integration of the NFS220 with industry standard network management systems.

The NFS220 provides three 1PPS time mark outputs. A unique feature allows precisely controlled delays to be inserted into these outputs to compensate for cable and other propagation delays. Compensation delay is independent for each output and has
Serial time code outputs are provided to allow time synchronization to be distributed to computers, displays, and other equipment requiring precision time. Two outputs are dedicated to Have Quick time code. Two outputs (one modulated, one DC level shift) may be user selected from IRIG A, IRIG B, IRIG E, IRIG G.

Four low phase noise 10 MHz sine wave outputs from the disciplined oscillator are provided. Signal amplitude is software settable.

All outputs are provided with activity detectors. Loss of any output is indicated by means of a individual front panel alarm LED as well as through the network interface or a discrete alarm output.


Product Specifications
Product Data Sheet
User Manual

NFS220 Specifications  
   
Satellite Signal GPS L1, 1575.42 MHz
Satellite Code C/A 1.023 MHz
Receiver Type Parallel 16 Channel. All-in view satellites tracked continuously and simultaneously
Warm Start  
Autonomous Start  
Cold Start Requirements Automatic: No input of time or position required
Position Accuracy 2.4 m horizontal, 5 m altitued with respect to WGS84 after 24 hour position averaging
Timing Accuracy (Tracking Satellites) +/- 100ns. Absolute UTC Std. Deviation 15ns (OCXO)
Timing Accuracy (Holdover mode, +/- 5°C)  
   
1PPS Output  
Connector BNC (2) DB9 (1)
Level 0-5V or 0-10V into 50Ω link selectable by user
On Time Rising Edge
   
Network Interface  
Interface Type 10BaseT
Protocols TCP/IP, UDP, NTPv3, HTTP, SNMP v1
   
Serial Interface  
Type RS232 and RS422
Baud Rate 9600,N,8,1
   
Sine Wave Outputs  
No. of Outputs 4
Connector BNC
Frequency 10MHz
Level 0 -13dBm into 50 ohm Software Settable
   
Time Code 1 Output (Modulated)
Connector BNC
Code Type IRIG A135, B125, E115, G145 software selected
Control Functions IEEE 1344
Level 3 V p-p into 600 ohm (DCLS)
   
Time Code 2 Output  
Connector DB9
Code Type IRIG A005, B005, E005, G005
Selection same as modulated code
Levels DC level shift (0-5V)
   
Time Code 3,4 Output  
Connector BNC (1) DB9 (1)
Code Type Have Quick per ICD-GPS-060
Levels 0-5V
Alarm Status Voltage free relay
   
Status Indicator LED's Power
  Tracking Satellites
  Valid Time
  Holdover/ 12hr Holdover alarm
  Output Good/Fail (8 leds)
   
Environmental  
Temperature Instrument: -10 to +50°C
Humidity 95% non condensing
Power 85-265VAC 50/60Hz
Optional 12VDC, 24VDC, -48VDC, 125VDC
Dimensions 19" rack mount
  1.75" (1U) height, 7.5" depth, 17" width, 3.5lb Nom.
Weight 11lb typical
EMC Emmission To EN55022 as EN50024 FCC Part 15B, Class A
EMC Immunity To EN50082-1 as EN61000-4-2 ESD, IEC 801-3 HF Field, IEC 801-4 Burst