SATEC PM180 Operation Manual - Manual (Page 67)

‎Chapter 7 Programming the PM180 Generating Energy Pulses
PM180 Substation Automation Unit 65
Option Format/Range Default Description
Time
synchronization
input GPS IRIG-B, SNTP,
DI1-DI48 (digital
input 1-48) GPS
IRIG-B The external port receiving the time
synchronization signal. If no external
synchronization is used, set this option
to IRIG-B: when a signal is not present,
the PM180 automatically uses internal
RTC clock for time synchronization.
Time Synchronization Source
The PM180 receives the time synchronization signal either from a GPS clock having
an IRIG-B time-code output, or from an external device giving a pulse at the
beginning of the minute. If the IRIG-B option is selected but the IRIG-B signal is not
present on the device input, the PM180 automatically uses its internal RTC clock.
Using the IRIG-B
To use the IRIG-B input, select the GPS IRIG-B option and connect the GPS master
clock to the IRIG-B BNC connector on the front of the PM180.
When the IRIG-B signal is present on the device input, the PM180 automatically
synchronizes its clock with the GPS time each second, normally with accuracy better
than 1 millisecond if the time is locked to the GPS satellite time. If the GPS clock
loses the satellite signal, the clock continues to generate the IRIG-B time code
referenced to the last available satellite time, but the time quality may get worse.
Such signal losses can last from a few minutes to hours. During such outages the
time code generated by the GPS receiver is typically accurate to within a few
milliseconds over a 24-hour period.
You can check presence and quality of the IRIG-B signal through the RDM from the
Clock Setup Menu , through HyperTerminal (see Testing the GPS Master Clock in
Chapter 4) and via the Device Diagnostics .
If the IRIG-B signal is lost, the PM180 changes the time synchronization source to
the internal RTC in 5 minutes. When the IRIG-B signal is restored, the device
automatically acquires the GPS time.
If the IRIG-B signal is lost or time code quality changes (locked to the GPS satellite
time or unlocked), the corresponding events are automatically recorded to the device
Event log.
Using SNTP
Enable SNTP client operation and configure it if required (see Setting-Up SNTP
Client).
When an SNTP server is not available or when a connection with a server is
restored, the corresponding event is automatically recorded to the device Event log.
Using External Minute Pulses
External time synchronization pulses are delivered through one of the PM180 digital
inputs. If the digital input is selected as the time synchronization source, the external
pulse’s edge adjusts the device clock at the nearest whole minute. The time accuracy
is affected by the debounce time programmed for the digital input, and by the
operation delay of the external relay.
Daylight Savings Time
The daylight savings time option is enabled in the PM180 by default, and the default
daylight savings time change points are set for the U.S.A. When the daylight savings
time is enabled, the PM180 automatically adjusts the device clock at 02.00 AM when
daylight savings time begins/ends.
If the daylight savings time option is disabled, you need to manually adjust the device
clock for daylight savings time.
Generating Energy Pulses
The PM180 has seven total energy registers where it stores different kinds of
accumulated energies. The PM180 provides internal pulsed events when a
predefined amount of energy is added to the register. These pulses are linkable to
the relay outputs to generate energy pulses for external counters (see Programming
Relay Outputs), or to trigger the device control setpoints.