Time
The time parameters are found via menu path .
| Parameter | Values (Range) | Unit | Step | Default | Description |
|---|---|---|---|---|---|
| Synch source |
0=None 1=SNTP 2=Modbus 3=IEEE 1588 5=IRIG-B 9=DNP 17=IEC60870-5-103 |
1=SNTP | Time synchronization source | ||
| PTP Profile |
1=IEEE C37.238-2011 2=IEC 61850-9-3 |
1=IEEE C37.238-2011 | Profile Selection for the Precision Time Protocol | ||
| PTP domain ID | 0...255 | 1 | 0 | The domain is identified by an integer, the domainNumber, in the range of 0 to 255. | |
| PTP priority 1 1 | 0...255 | 1 | 128 | PTP priority 1. Internally 255 in Slave-only mode. | |
| PTP priority 2 1 | 0...255 | 1 | 128 | PTP priority 2. Internally 255 in Slave-only mode. | |
| PTP Slave-only |
0=False 1=True |
0=False | If true, the IED cannot become a clock master | ||
| Time master mode |
1=Master with finite holdover 2=Master with infinite holdover |
1=Master with finite holdover | Device Time Master Mode | ||
| Clear clock list |
0=False 1=True |
0=False | Clears the stored master clock list | ||
| Time Syn Src Tmm | 1...65535 | min | 1 | 3 | Time synchronization timeout for legacy protocols as clock source (Modbus, IEC103, IEC101, IEC104 and DNP) |
| Parameter | Values (Range) | Unit | Step | Default | Description |
|---|---|---|---|---|---|
| Local time offset | -840...840 | min | 1 | 0 | Local time offset in minutes |
| Parameter | Values (Range) | Unit | Step | Default | Description |
|---|---|---|---|---|---|
| IP SNTP primary | 192.168.2.166 | IP address for SNTP primary server | |||
| IP SNTP secondary | 192.168.2.165 | IP address for SNTP secondary server |
| Parameter | Values (Range) | Unit | Step | Default | Description |
|---|---|---|---|---|---|
| DST in use |
0=False 1=True |
1=True | DST in use setting | ||
| DST on time (hours) | 0...23 | h | 2 | Daylight saving time on, time (hh) | |
| DST on time (minutes) | 0...59 | min | 0 | Daylight saving time on, time (mm) | |
| DST on date (day) | 1...31 | 1 | Daylight saving time on, date (dd:mm) | ||
| DST on date (month) |
1=January 2=February 3=March 4=April 5=May 6=June 7=July 8=August 9=September 10=October 11=November 12=December |
5=May | Daylight saving time on, date (dd:mm) | ||
| DST on day (weekday) |
0=reserved 1=Monday 2=Tuesday 3=Wednesday 4=Thursday 5=Friday 6=Saturday 7=Sunday |
0=reserved | Daylight saving time on, day of week | ||
| DST off time (hours) | 0...23 | h | 2 | Daylight saving time off, time (hh) | |
| DST off time (minutes) | 0...59 | min | 0 | Daylight saving time off, time (mm) | |
| DST off date (day) | 1...31 | 25 | Daylight saving time off, date (dd:mm) | ||
| DST off date (month) |
1=January 2=February 3=March 4=April 5=May 6=June 7=July 8=August 9=September 10=October 11=November 12=December |
9=September | Daylight saving time off, date (dd:mm) | ||
| DST off day (weekday) |
0=reserved 1=Monday 2=Tuesday 3=Wednesday 4=Thursday 5=Friday 6=Saturday 7=Sunday |
0=reserved | Daylight saving time off, day of week | ||
| DST offset | -720...720 | min | 1 | 60 | Daylight saving time offset |
In IEEE 1588 v2, the PTP domain is a logical grouping of clocks that synchronize to each other using the protocol but that are not necessarily synchronized to clocks in another domain.
PTP priority 1 and PTP priority 2 are used in the execution of the best master clock algorithm in which lower values take precedence. Priority 1 is the first one used to decide the clock master.
PTP profile is used to select the profile which affects PTP announce frame format. Possible selection are "IEEE C37.238-2011" which is often referred as old Power profile and "IEC 61850-9-3" which is a profile for power utility automation.
Clear clock list is used to clear the stored master clock list. For more information, see time synchronization in the technical manual.
Best master clock algorithm
The best master clock algorithm compares data describing two clocks to determine which data describes the better clock. This algorithm is used to determine which of the described clocks in several announce messages received by the local clock port is the best clock. It is also used to determine whether a newly discovered clock is better than the local clock.
The comparison algorithm is based on pair-wise comparisons of attributes with the following precedence.
- Priority 1
- Clock class
- Clock accuracy
- Clock stability
- Priority 2
- Clock identity: A tie-breaker based on unique identifiers
The TxTR ALARM output activates in the SMV receiver if transfer is made to a IEEE 1588 v2 master that has 8 ms or more offset compared to the previous master. The ALARM output stays on for a period of 11...33 s.
Time synchronization monitoring values
The time synchronization monitoring values are found via menu path .
| Description | Value |
|---|---|
| Synch source | IEEE 1588 master |
| IEEE 1588 slave | |
| Synch status | Up |
| Down | |
| Synch accuracy | 0...26 bits |
Sync accuracy indicates the synchronization accuracy in number of fractional bits and can be calculated from the number of bits according to a formula.
|
Bits |
Accuracy |
|---|---|
|
17 |
8 µs |
|
18 |
4 µs |
|
19 |
2 µs |
|
20 |
1 µs |
|
21 |
500 ns |
|
22 |
250 ns |
|
23 |
125 ns |
|
24 |
62.5 ns |
|
25 |
31.25 ns |
IEEE 1588 v2 monitoring values
The IEEE 1588 v2 monitoring values are found via menu path .
IEEE 1588 v2 monitoring values| Description | Value |
|---|---|
| PTP gm identity | |
| PTP gm time Src | Atomic clock |
| GPS | |
| Terrestrial radio | |
| PTP | |
| NTP | |
| Hand set | |
| Other | |
| Internal oscil. | |
| PTP gm accuracy |
Within a domain, grandmaster is the clock that is the ultimate source of time for clock synchronization using the PTP protocol.
PTP gm identity indicates the identity of the master clock.
PTP gm time Src indicates the source of time announced by the grandmaster clock.
PTP gm accuracy indicates the accuracy announced by the grandmaster clock.
SMV accuracy monitoring values
The SMV accuracy monitoring values are found via menu path .
| Description | Value |
|---|---|
| SMV synch accuracy | InternalClock |
| LocalAreaClock | |
| GlobalAreaClock | |
| Local synch accuracy | |
| Max Dev Sync Acc |
SMV synch accuracy value "InternalClock" indicates that the SMV is either not in use or it is not synchronized with IEEE 1588 v2. "LocalAreaClock" indicates that SMV is synchronized to a local area clock and "GlobalAreaClock" indicates that SMV is synchronized to a global time reference such as GPS.
Local synch accuracy indicates the time synchronization accuracy in microseconds.
Max Dev Sync Acc indicates the maximum clock deviation when the clock accuracy was over 4 μs.
During changing network conditions where e.g. main GPS clock is lost, the system elects a new PTP master utilizing the best master clock algorithm. Due to time accuracy sensitivity of SMV applications, it is advisable to have more than one PTP master capable device in the network, for uninterrupted SMV quality (smpSync). By default settings, the relay can act as a temporary backup PTP master, until main GPS clock is restored. There is also possibility to deny this operation, by setting "PTP slave-only” TRUE value in time synchronization menu. However, it is good to be aware that SMV application cannot operate properly (SmpSync=none) without an accurate PTP master constantly available in the network.