5.
Alarms
This section describes the GridTime
™
3000 GNSS Time Server’s alarms, how they can be monitored, and what
corrective action is required when they occur.
The GridTime 3000 generates an alarm when an event that causes a risk to the operation of the device occurs.
Some alarms are expected in isolated occurrences due to signal quality fluctuations. These alarms only show an
installation problem when they become recurring. Recurring means the alarm does any of the following:
• never clears
• triggers and clears repeatedly for an extended period
• appears again when the unit is power cycled.
Some alarms may indicate that maintenance needs to be performed on the device or installation, and/or may require
technical support to be contacted. See
11.10. Contacting Technical Support
.
• Low satellites alarm: not enough usable GNSS satellites detected. If recurring, it requires the antenna
installation to be modified.
• Power supply alarm: a power supply has failed. Technical Support may need to be contacted.
See
for a detailed description of the trigger and clearance conditions for each of the GridTime
3000's alarms.
5.1
Alarm Monitoring
This section describes the various alarm monitoring methods used with the GridTime 3000.
All active alarms are listed on the alarms tab of the device’s LCD and on the dashboard of its Clock Management
Tool (CMT) in priority order.
The highest priority alarm is also abbreviated and displayed under the alarm icon on the main screen of the device’s
LCD. See
If notifications have been configured, alarms cause SNMP or Syslog notifications to be sent from the admin Ethernet
port to a list of user-defined IP addresses.
A notification is sent when an alarm is triggered or cleared. All alarms map to a unique notification, but not all
notifications map to an alarm, as some notifications simply describe standard operational events.
• antenna current high event: Generates alarm, and trigger and clearance notifications.
• first sync achieved event: Does not generate alarms, only a trigger notification.
The device includes two alarm relay ports, consisting of two 3-pin phoenix form C alarm relay contacts. Each alarm
relay port includes a normally closed (NC) contact, a common (C) contact, and a normally open contact (NO).
Each alarm relay port can have any alarms enabled for it through configuration. If any of the alarms enabled on an
alarm relay port become active, the port goes from the non-alarm state to the alarm state. The alarm state contact
impedances are as follows:
• the impedance between the NC an C contacts becomes under 40 ohm(Ω)
• the impedance between the NO and C contacts becomes open circuit.
When all the mapped alarms clear, the port goes to the non-alarm state again. The non-alarm state contact
impedances are as follows:
• the impedance between the NC and C contacts becomes open circuit
• the impedance between the NO and C contacts becomes under 40Ω.
Alarms
©
2022 Microchip Technology Inc.
and its subsidiaries
Manual
DS00004572A-page 26
