DOC 6511_Release K
ATS-6511A/B/C Users Guide
17
The system is set up to use the legacy fiber mode by default. The following shows the operator
how to set the two-way mode and verify the system settings (
settings fiber:mode
).
ATS-6511A>fiber_mode two_way
[OK] 2013-08-13T17:37:30Z
ATS-6511A>settings fiber:mode
two_way
[OK] 2013-08-13T18:01:06Z
2.6.2 Two Way Disabled (4372A-T Fiber Card)
There may be some installations where the two way exchange over the fiber is not desired. This
mode can be disabled using the
fiber_mode
command as shown below. Use the
settings
fiber:mode
command to verify the system settings. If these settings are correct ensure you use the
save
command to save the system settings
ATS-6511A>fiber_mode two_way_disabled
[OK] 2011-06-06T19:35:52Z
ATS-6511A>settings fiber:mode
two_way_disabled
[OK] 2013-08-13T18:01:26Z
Note:
Refer to Section 2.6.4 to properly calibrate the system. Also note this is NOT the same as
the legacy mode of operation. The ATS-6511 will not lock to the fiber input if the ATS-6501 has
a 4372A Card and you are operating the ATS-6511 in the
two-way_disabled fiber_mode.
2.6.3 One-Way Fiber Calibration
For system applications requiring the highest level of accuracy, the system should be calibrated at
Symmetricom. This process involves installing the ATS-6501, user’s antenna and antenna cable,
ATS-6511 and fiber optic cable(s) at the factory and comparing the PPS outputs to a system
which has a known offset to UTC(USNO). Once the calibration is complete, the delay values are
provided to the customer when the system is delivered. The PPS outputs will be accurate to the
precise calibration levels specified in Appendix A as long as the user installs the antenna at a
surveyed location. If a surveyed antenna location is not available, the ATS-6501 can be used to
survey the location. Refer to the ATS-6501 manual for more information on installing the ATS-
6501 and antenna(s).
A coarse calibration of an ATS-6511 in a system is accomplished by accounting for the individual
system delays and combining them to determine the overall delay of the system. This method is
generally less accurate because the individual delays in the system are estimated and may not be
entirely accurate. Refer to the ATS-6501 manual for more information on calculating the delay of
the ATS-6501. Equation 2-1 gives the general formula for performing a coarse calibration of the
cabling to the ATS-6511.
f_Measure)
per_unit_o
efraction(
Index_of_r
Fiber*
Length_of_
onds)
_Delay(
ATS_
=
sec
6511
Eq. 2-1
Содержание ATS-6511A
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