Allen-Bradley armorstratix 5700, Руководство пользователя, Страница: 150 / 458

150 Rockwell Automation Publication 1783-UM007I-EN-P - December 2017
Chapter 3 Configure Switch Features
Global Navigation
Satellite System (GNSS)
The built-in GNSS receiver enables a Stratix 5410 switch to determine its own
location and get an accurate time from a satellite constellation. The switch can
then become the Grandmaster clock for time distribution in the network.
GNSS Hardware
The switch uses a GNSS receiver with precise frequency and phase outputs for
the host system. When connected to an external GNSS antenna, the receiver
can acquire GNSS satellite signals, track as many as 32 GNSS satellites, and
compute location, speed, heading, and time. It provides an accurate one
pulse-per-second (PPS) and stable 10 MHz frequency output. For more
information, see
GNSS Signaling on page 151 .
GNSS hardware supports the following frequency bands:
•
GPS/NAVSTAR—Global Positioning System (USA: L1)
•
GLONASS—Global'naya Navigatsionnaya Sputnikovaya Sistema
(Russia: L1/G1)
•
BeiDou—China (including B1-2)
GNSS Software
As of IOS release 15.2(6)E0a and later, the GNSS software feature performs
the following functions:
•
Configures the GNSS receiver.
•
After the receiver gains lock, the software performs the following
functions once per second:
–
Reads the new time and date.
–
Reads the corresponding pulse-per-second (PPS) time stamp from
the hardware.
–
Feeds the time and date and PPS time stamp into the Time Services
SW Virtual Clock/Servo for GNSS. The GNSS SW Virtual Clock
time can then be used to drive Precision Time Protocol (PTP)
output.
IMPORTANT GNSS is supported only on Stratix 5410 series B switches with IOS release
15.2(6)E0a and later.
To use the GNSS software feature on the switch, you must obtain an external
GPS antenna from a third-party manufacturer.
IMPORTANT The Galileo satellite system is not available in the current release.