Appendix A
Specifications
©
National Instruments Corporation
A-7
NI PXI-6682 User Manual
Power Requirements
Synchronization Accuracy
Voltage (V)
Typical
Maximum
+3.3 V
450 mA
700 mA
+5 V
170 mA
235 mA
+12 V
135 mA
180 mA
–12 V
0 A
0 A
Test
1
Specification
GPS
2
±100 ns, < 13 ns standard deviation
IEEE 1588 3 m Ethernet direct connection
3
±47 ns, < 10 ns standard deviation
IEEE 1588 through a hub
3,4
±210 ns, < 35 ns standard deviation
IEEE 1588 through a switch
3,5
±25
μ
s, < 150 ns standard deviation
IRIG-B DC
±55 ns, < 13 ns standard deviation
IRIG-B AM matching
6,7
±1
μ
s, < 220 ns standard deviation
IRIG-B AM to source
7
±5
μ
s, < 500 ns standard deviation
PPS
±47 ns, < 10 ns standard deviation
1. All synchronization measurements were done by recording the offset between PPS signals generated by two PXI-6682 boards inside closed
PXI-1031 chassis, at ambient room temperature conditions. Synchronization was performed for 15 minutes before testing began. All test
durations were 12 hours.
2. For the GPS test, two PXI-6682 boards were independently synchronizing to GPS and configured to generate a PPS. The specification above
represents empirical results. Please note that GPS satellites are only guaranteed to be within 100ns of UTC. Therefore, the offset between any
two devices synchronizing can be as high as 200 ns plus the offset of that device to GPS.
3. Sync interval of 1 second was used for IEEE 1588 tests, and all Ethernet connections were 100 Mbps.
4. Netgear DS104 Hub used.
5. Airlink 101 Gigabit over copper switch used. For this test, a moderate amount of non-1588 Ethernet traffic was present on the switch.
6. IRIG-B AM matching specification was obtained by setting two PXI-6682 boards to synchronize independently to the same IRIG-B AM
source and generate a PPS. The offset between their PPS signals was then measured over a 12 hour period.
7. IRIG-B performance depends on IRIG-B source stability and quality.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
