ABB ret650, Applications Manual

Page: 309 / 392

IEC16000039-1-en.vsdx
IEC16000039 V1 EN-US
Figure 105: ECT screen with Redundancy set to PRP-1 on Access point 1 and
HSR Access point 3
15.3 Merging unit
15.3.1 Application
GUID-E630C16F-EDB8-40AE-A8A2-94189982D15F v1
The IEC/UCA 61850-9-2LE process bus communication protocol enables an IED
to communicate with devices providing measured values in digital format,
commonly known as Merging Units (MU). The rear access points are used for the
communication.
The merging units (MU) are called so because they can gather analog values from
one or more measuring transformers, sample the data and send the data over
process bus to other clients (or subscribers) in the system. Some merging units are
able to get data from classical measuring transformers, others from non-
conventional measuring transducers and yet others can pick up data from both
types.
1MRK 504 169-UEN A
Section 15
Ethernet-based communication
Transformer protection RET650 2.2 IEC 303
Application manual