ABB RES670 Applications Manual page 333

1MRK 511 407-UEN C
Phasor measurement unit RES670 2.2 IEC
Application manual
GPSSyncErr: when GPS synchronization is lost, synchronization of the line
differential function continues for 16 s based on the stability in the local IED
clocks. After that, setting Block blocks the line differential function or setting Echo
keeps it on by using the Echo synchronization method.
Using Echo in this case is safe only if there is no risk of varying
transmission asymmetry.
CommSync defines the Master and Slave relation in the communication system,
and should not be mistaken for the synchronization of line differential current
samples. When direct fiber is used, one LDCM is set as Master and the other as
Slave. When a modem and multiplexer is used, the IED is always set as Slave
because the telecommunication system provides the clock master.
OptoPower has two settings: LowPower and HighPower.
Short-range LDCM: Use LowPower for fibres 0 – 1 km and HighPower for fibers
greater than 1 km.
Medium-range LDCM: Typical distance 80 km for both LowPower and
HighPower.
Long-range LDCM: Typical distance 120 km for both LowPower and HighPower.
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 LowPower
setting to minimize the power consumption and keep the heat dissipation at
minimum.
The HighPower setting adds 3 dBm extra optical power and can be used to increase
the margin at distances close to maximum.
Table 33: Optical budgets with C37.94 protocol
Type of LDCM Short range (SR)
Type of fibre Multi-mode fiber
glass 50/125 μm
Modem type 1MRK0002122-
AB
Contact type ST
Table continues on next page
Remote communication
Short range (SR) Medium range
(MR)
Multi-mode fiber Single-mode fiber
glass 62.5/125 glass 9/125 μm
μm
1MRK0002122- 1MRK002311-AA
AB
ST FC/PC
Section 20
Long range (LR)
Single-mode fiber
glass 9/125 μm
1MRK002311-BA
FC/PC
327