Spectracom VelaSync 1225, Руководство пользователя

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IRIG DCLS Input
Accepts IRIG formats A, B, G; NASA36; IEEE 1344 pulse width codes (does
not accept Manchester modulated codes)
RS-485 differential input: –7V to +12 V common mode voltage input range,
200 mV
p-p
differential voltage threshold
Single-ended input:
+1.3 V
VIL min
, +2 V
VIH max
+1.45 V
VIL typ
, +1.85 V
VIH typ
GPIO Inputs
Amplitude: 0V to +5.5 V input range, +0.8 V
VIL
, +2.0 V
VIH
Polarity (selectable): Positive or negative
Input impedance: <150 pF capacitive
50 ns active pulse width minimum; 50 ns minimum between pulses
Repetition rate. More than 10,000 events per second
Resolution: 5 ns
Outputs
1 PPS Outputs
1Hz pulse, rising edge or falling edge active (selectable)
40 ns to 900 ms active pulse width (selectable, 200 ms default)
Rise time: <10 ns
Signal level: TTL compatible, 4.3 V
min
, base-to-peak into 50 Ω
[PCIe only: TTL compatible, 2.2 V minimum, base-to-peak into high imped-
ance]
Accuracy: Positive edge within ±[X] nanoseconds of UTC when locked to a
valid 1PPS input reference (for [X], see table below).
Table 1-2: 1 PPS output accuracy
TCXO OCXO
OCXO (Rugged
Option, cPCI & VPX
only)
Accuracy to UTC (1-
sigma locked to GPS)
±50
ns ±50
ns ±25 ns
1.4 Technical Specifications
CHAPTER
1
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VelaSync User's Manual Rev. 3 7