Brandywine Portable Timing Unit - Introduction to the Portable Timing Unit; Reference Input Sources; Time Keeping Mechanisms; Network Interface Capabilities

!
!
!
MANUAL&P/N&900000118&REV&D&
5!
+
1 Introduction(
The!Portable!Timing!Unit!(PTU)!is!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,!or!an!serial!time!code!
such!as!IRIG!B!or!Have!Quick.!
Operation!of!the!unit!can!be!monitored!via!an!Ethernet!interface,!or!by!means!of!
front!panel!indicators!and!displays.!Outputs!are!1PPS,!Have!Quick,!IRIG!B!Time!Code!
and!Network!Time!Protocol!(NTP).!
The!unit!is!mounted!in!a!rugged,!weather!proof!case!that!may!be!easily!transported!
to!the!point!of!use.!When!AC!power!is!available,!the!PTU’s!built-in!power!supply!will!
automatically!charge!the!internal!batteries.!
Reference+Input+Sources!
The!PTU!is!extremely!flexible!in!its!ability!to!synchronize!to!a!variety!of!timing!
sources.!Available!references!are:!
• 16!channel!GPS!SPS!receiver!(standard)!!
• 12!channel!GB-GRAM!SAASM!GPS!receiver!(optional)!!
• IRIG!B!Time!Code!(standard)!!
• HaveQuick/1PPS!from!external!GPS!receiver!(standard)!
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!!
• Temperature!Compensated!Crystal!Oscillator!(TCXO)!-option!!
• Oven!Controlled!Crystal!Oscillator!(OCXO)!standard!!
• 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!
• 1PPS!1!Pulse!Per!Second!Signal!Time!Mark!!
• Have!Quick!Time!Code!!
• IRIG!B!Time!Code!
• NTP!