Chapter 4
1PPS Wander Analysis
Measuring TIE and calculating MTIE/TDEV
T-BERD/MTS 5800 Timing Expansion Module User Manual
July 2017
22112315, Rev. 004
Page 43
4
Under
Mode
, select
1PPS Analysis
, then specify the source of the reference
timing signal:
–
If you want to use an external 1PPS reference clock:
-
Select
1 PPS IN 1
.
-
In
Differential Time Bias
, specify the time difference between the refer-
ence
1 PPS IN 1
and the analyzed
1 PPS IN 2
input in nanoseconds.
-
Connect the cable providing the external reference signal to the TEM
Module connector labeled
1 PPS IN 1
.
-
Connect the cable providing the signal to be analyzed to the TEM
Module connector labeled
1 PPS IN 2
.
–
If you want the TEM to use GNSS for reference timing:
-
Verify that you have connected a GNSS antenna (see
).
-
Select
GNSS 1 PPS
.
-
Use a cable to provide a signal from the
1 PPS OUT
connector to the
1 PPS IN 1
connector. This signal will serve as the reference signal.
-
Connect the cable providing the signal to be analyzed to the TEM
Module connector labeled
1 PPS IN 2
.
5
In
Oscillator On at Startup
do the following:
–
If you want the oscillator to turn on automatically when the test instrument is
turned on (and start to warm up immediately), select the checkbox.
–
If you do not want the oscillator to turn on automatically when the test instru-
ment is turned on, clear the checkbox.
6
In
Holdover Drift Allowed (ns)
, specify the maximum acceptable drift allowed
while operating the module in holdover mode (in nanoseconds). The module will
then estimate the time remaining before the oscillator drifts to an unacceptable
level, and provide the time remaining in the Oscillator results category. For details,
see
“Oscillator Results” on page 58
.
7
On the left of the screen, select
1 PPS Analysis
.
The
1 PPS Analysis
setup tab appears.
8
Under
1PPS Thresholds
, do the following
a
Select the box to the left of each setting that will be used to establish pass /
fail thresholds.
b
For each enabled setting, specify the allowable threshold in the unit of
measure indicated. For example, if the Maximum allowable MTIE threshold is
enabled, specify the maximum allowable value in nanoseconds (ns).
9
On the left of the screen, select
Timed Test
.
The
Timed Test
setup tab appears.
10
Specify a duration for the test that will yield appropriately accurate results. Test
results will be frozen after the test ends.
11
Verify that the
Ref Clk Valid
and
Input Clk Valid
LEDs are green.
12
Select
Restart
.
