least equipped with a real-time operating system, that is not a PC with SNTP server
software. The SNTP server should be stable, that is, either synchronized from a stable
source like GPS, or local without synchronization. Using a local SNTP server without
synchronization as primary or secondary server in a redundant configuration is not
recommended.
21.4 PTP requirements
GUID-741CC863-D760-49D6-85B2-AFECA222A8C3 v1
For PTP to perform properly
, the Ethernet equipment that is used needs to be compliant
with IEEE1588. The clocks used must follow the IEEE1588 standard BMC (Best
Master Algorithm) and shall, for instance, not claim class 7 for a longer time than it
can guarantee 1us absolute accuracy.
21.5 Sample specification of communication requirements
for the protection and control terminals in digital
telecommunication networks
GUID-0A9F36AF-3802-42FE-8970-4662798C19D1 v2
The communication requirements are based on echo timing.
Bit Error Rate (BER) according to ITU-T G.821, G.826 and G.828
•
<10
-6
according to the standard for data and voice transfer
Bit Error Rate (BER) for high availability of the differential protection
•
<10
-8
-10
-9
during normal operation
•
<10
-6
during disturbed operation
During disturbed conditions, the trip security function can cope with high bit error
rates up to 10
-5
or even up to 10
-4
. The trip security can be configured to be
independent of COMFAIL from the differential protection communication supervision,
or blocked when COMFAIL is issued after receive error >100ms. (Default).
Synchronization in SDH systems with G.703 E1 or IEEE C37.94
The G.703 E1, 2 Mbit shall be set according to ITU-T G.803, G.810-13
• One master clock for the actual network
• The actual port Synchronized to the SDH system clock at 2048 kbit
• Synchronization; bit synchronized, synchronized mapping
Section 21 1MRK 505 370-UUS A
Requirements
534 Busbar protection REB670 2.2 ANSI
Application manual
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