Orolia Spectracom VelaSync 1232, Руководство пользователя

Страница: 18 / 268

1.4.1.3 Oscillator
Table 1-1:
Oscillator accuracies
OCXO Rb
Accuracy to UTC
(1 sigma locked to
GPS)
50 ns 25 ns
Holdover Accuracy
(loss of GPS signal after 2 weeks locked, constant temperature)
After 4 hours 1
μ
s 0.2
μ
s
After 24 hours 25
μ
s 1
μ
s
Notes :
• Accuracy to UTC is measured by comparing the internal 1PPS with the GPS ontime point.
• When ordering a VelaSync unit, either an OCXO or Rubidium oscillator must be specified.
• The specifications are subject to a steady environment temperature.
1.4.2 I/O Connectors
1.4.2.1 Timing Connector
The pre-installed TSync-model 25-pin Micro D-Sub Connector, when combined with the
adaptor cable and breakout cable (both included), provides the following I/O options:
Inputs:
1 PPS Input
1 Hz pulse, rising edge or falling edge active (selectable); 100 ns minimum
pulse width
Amplitude: 0 V to +5.5 V input range, +0.8 V
VIL
, +2.0 V
VIH
Input impedance: <150 pF capacitive
IRIG AM Input
Accepts IRIG formats A, B, G; NASA36; IEEE 1344
Amplitude: 500 mV
p-p
to 10 V
p-p
Modulation ratio: 2:1 minimum, 6:1 maximum
Input impedance: 10 kΩ minimum
DC Common Mode Voltage: ±150 V
DC
maximum
Input Stability: Better than 100 ppm
6
CHAPTER
1
•
VelaSync 1232 User Manual Rev. 4
1.4 Technical Specifications