VeEX RXT-6000e, User Manual

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2. Max TIE: Maximum positive TIE value that has been recorder since the beginning of the test
3.
Min TIE:
lowest or negative TIE value that has been recorded since the beginning of the test. Since
wander measurements always start with a TIE=0, then the minimum value can only be zero or negative.
4. MTIE: Denotes the maximum span of TIE values recorded since the beginning of the test. In this
summary, MTIE = MaxTIE – MinTIE. It gives users an idea of how much the signal under test is
wandering
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11.4.2 Advanced Clock Wander & Phase Measurements
The test set may offer clock wander and phase error measurement options (or licenses) that add verification of stability
(wander) and accuracy (absolute phase error) on external (physical) clock signals. Those signals could be from
reference clocks or recovered clock outputs from remote or slave terminals (SDH/SONET, PDH/DSn, SyncE, PTP,
GNSS/GPS, Rb clocks, etc.)
The results are the similar to the ones obtained by measuring wander on data interface ports (SDH/SONET, PDH/DSn,
SyncE or PTP). The main difference is that the advanced clock wander measurements are performed on a physical (not
internally recovered) clock signal.
This feature is usually an independent Test Mode and not linked to any particular data transmission interface.
11.4.2.1 Clock Wander and Phase Measurements (Optional)
The “Clock Wander & Phase Measurements” option offers short and long term Wander measurements for frequency
sources (e.g. 1.544, 2.048Mbps or 1.544, 2.048, 10MHz or 1PPS) and Phase Error measurements for timing sources
(i.e. 1PPS) and can save the TIE or TE measurements to a FAT32 USB Memory stick for further analysis. The test set
itself may also offer a built-in MTIE/TDEV Wander Analysis option to analyze the data or it can also be done by
using the free VeEX Wander Analysis PC Software that can be downloaded from www.veexinc.com
Both, Wander and Phase Error, measurements require a stable and accurate reference clock source, which can be an
external source connected to the CLK (SMA) input port or optional optional built-in GPS and Chip-scale Atomic
Clock references.
The built-in GPS hardware option provides a (raw) 1PPS timing signal (clock), aligned to the standard second,
and can be used to discipline the built-in atomic clock. The direct use of this raw “GPS 1PPS” alone is not
recommended for wander or phase measurements. It should be combined with the Atomic Clock to filter and
stabilize the timing signal
The built-in Atomic Clock hardware option can provide highly stable frequency references on its own (Atomic
1PPS and Atomic 10 MHz), suitable for wander measurements
When disciplined by the internal GPS receiver, the Atomic Clock 1PPS can also be used as a very stable and
accurate absolute timing reference aligned to the standard second (1PPS) or very accurate and stable frequency
reference (10 MHz)
External clock signals, directly traceable to PRC or PRTC, can also be used as a reference for even more
accurate results (e.g. high-quality GPS-disciplined OCXO, Rb or Cs clock sources)
While wander (stability) measurements use high precision frequency references, the absolute phase error (also known
as Time Error ot TE) requires an accurate 1PPS timing signal, aligned to the standard second (UTC). The 1PPS can be
sourced from a high precision GPS-disciplined clock (built-in option or external).
The Wander (TIE) and Phase (TE) data logs can be saved in real time to a USB Memory using VeEX proprietary
format (to be analyzed by the built-in or PC-based MTIE/TDEV Analysis software) or exported to an open CSV
format.
Test Setup
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