ABB Relion REC670 Applications Manual page 439

1MRK 511 358-UEN A
TerminalNo , but equal to the TerminalNo of the remote end LDCM. In the remote IED the
TerminalNo and RemoteTermNo settings are reversed as follows:
• LDCM for slot 302: Set
• LDCM for slot 303: Set
DiffSync : Here the method of time synchronization, Echo or GPS , for the line differential
function is selected.
GPSSyncErr : If GPS synchronization is lost, the synchronization of the line differential function
will continue during 16 s. based on the stability in the local IED clocks. Thereafter the setting
Block will block the line differential function or the setting Echo will make it continue by using
Echo synchronization method. It shall be noticed that using Echo in this situation is only
the
safe as long as there is no risk of varying transmission asymmetry.
CommSync : This setting decides the Master or Slave relation in the communication system
and shall not be mistaken for the synchronization of line differential current samples. When
direct fibre is used, one LDCM is set as
multiplexer is used, the IED is always set as
provide the clock master.
OptoPower has two settings: LowPower and HighPower .
Short-range LDCM: Use
km.
Medium-range LDCM: Typical distance 80 km for both
Long-range LDCM: Typical distance 120 km for both
An optical budget calculation should be made for the actual case. For medium range LDCM and
long range LDCM the recommendation is to use the
consumption and keep the heat dissipation at minimum.
HighPower setting adds 3 dBm extra optical power and can be used to increase the
The
margin at distances close to maximum.
Table 47:
Type of LDCM
Type of fibre
Modem type
Contact type
Table continues on next page
Application manual
TerminalNo to 2 and RemoteTermNo to 1
TerminalNo to 4 and RemoteTermNo to 3
The redundant channel is always configured in the lower position, for example
• Slot 302: Main channel
• Slot 303: Redundant channel
The same is applicable for slot 312-313 and slot 322-323.
Echo in this situation is safe only as long as there is no risk of varying
Using
transmission asymmetry.
LowPower for fibers 0 – 1 km and HighPower for fibers greater than 1
Optical budgets with C37.94 protocol
Short range (SR)
Multi-mode fiber
glass 50/125 μm
1MRK0002122-AB
ST
Master and the other one as Slave . When a modem and
Slave , as the telecommunication system will
LowPower and HighPower .
LowPower and HighPower .
LowPower setting to minimize the power
Short range (SR) Medium range (MR)
Multi-mode fiber Single-mode fiber
glass 62.5/125 μm glass 9/125 μm
1MRK0002122-AB 1MRK002311-AA
ST FC/PC
Section 19
Remote communication
Long range (LR)
Single-mode fiber
glass 9/125 μm
1MRK002311-BA
FC/PC
433