GPS Grandmaster Clock
74
RT430-TM-EN-5
6. MAINTENANCE
6.1
Synchronism failure (Locked Signaling)
When the unit is operating without synchronism reference in the GPS antenna, the failure is signaled in
different ways: Local interface, Web Interface, signaling relay, and data packets from IRIG-B, NTP, PTP e
SNMP protocols.
When synchronism failure is detected, some providence is recommended:
Check for configuration being transmitted to the unit. During transmission, the unit should
momentarily go out of operation to reboot. This behavior is normal and no action is required. The
L
OCKED
indicator will lit as soon as the unit resumes operation.
Make sure the GPS antenna is properly connected to the unit, as the specifications of
Chapter 2
Make sure the antenna cable being used is in accordance with the specifications presented in
Chapter 1
Make sure the unit is synchronized with at least 4 GPS satellites by checking the Web Interface.
Otherwise, check the location of the antenna, making sure that it is installed according to the
recommendations of
Chapter 2
6.1.1
Locked indicator (IHM)
The L
OCKED
indicator located in the front panel will be off when there is no synchronism reference in the
GPS antenna input. As soon as a GPS antenna is connected, the indicator will start blinking while it
downloads a satellite almanac. This behavior is normal and no actions are necessary. The L
OCKED
indicator
will stop blinking and stay lit as soon as the download is completed (it may take a few minutes when a unit is
moved over long distances or has been out of operation for a long period of time).
6.1.2
Remote monitoring (Web Interface)
In the monitoring area of the Web Interface it is shown the information L
OCKED
and the number of satellites
when there is synchronism reference in the GPS antenna input, and U
NLOCKED
when reference is
disconnected.
6.1.3
Dry-contact relay (L
OCKED
)
RT430 has a dry-contact normally closed for remotely signaling the synchronism state of the unit. As the unit
is powered up, the dry-contact L
OCKED
is normally closed. Synchronism information from at least 4 GPS
satellites is required for the dry-contact to open. In case the unit loses GPS satellite reference, the dry-
contact closes signaling synchronism loss.