Brandywine's Portable Timing Unit (PTU) is a low cost, battery operated, transportable timing system that is designed to provide precise time of day at point of use. The PTU may be automatically synchronized by means of either GPS signals including SAASM GPS, or by a serial time code such as IRIG B or Have Quick. Outputs include: NTP, IRIG A, IRIG B, IRIG G, Have Quick, and 1PPS. A range of options are available for the oscillator which include: Rubidium, OCXO, or TCXO. Built in a rugged, weather-proof case the PTU is easily transportable to any location and can be used in all weather conditions to give precise Time and Frequency.
Once synchronized to the selected reference, the PTU will use the reference to continuously calibrate its internal oscillator so that accurate time can be maintained in the absence the reference. Front panel LEDs indicate the reference type in use, and whether time is valid. The PTU can be configured to always use a particular reference source, or automatically select whatever source is available.
Time Keeping
The internal time of the PTU is maintained by a high precision oscillator. Selection of the oscillator type will determine the accuracy of the PTU when its reference, (such as GPS) is not available. Available internal oscillator options are:
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Temperature Compensated Crystal Oscillator (TCXO) -option
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Oven Controlled Crystal Oscillator (OCXO) standard
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Atomic Rubidium Oscillator – option
Network Interface
The PTU incorporates an Ethernet connection that provides a convenient means of monitoring status of the instrument via a computer and simple web browser. This interface is also used to provide NTP synchronization, firmware updates and Browser based setup features.
Output Signals
The PTU provides a variety of timing signal outputs, giving maximum application flexibility
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1PPS 1 Pulse Per Second Signal Time Mark
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Have Quick Time Code
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IRIG B Time Code
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NTP
Internal Battery Backup
The PTU contains an internal 7Ah battery that will operate the system in the event prime power is lost. The battery charge is monitored and maintained whenever prime power is applied to the PTU. Status is indicated by front panel LED’s. Battery life is dependent upon the oscillator configuration selected and the ambient temperature, but 5 hours is typical for the OCXO version.
Time Display
An 11 digit display indicates Years, Days, Hours, Minutes and Seconds. The illumination of the display is controlled by a front panel switch to conserve battery life.
External Event Input
The PTU includes an external event input that will latch the time of external events applied as pulses to this input. The time tags are stored in an internal memory and may be displayed and retrieved using the network interface.
Weatherproof Enclosure
The PTU is housed in a sturdy weatherproof enclosure that is suitable for outdoor use in all weather conditions.