Time Synchronization; Alarm Signals - Hitachi Relion 650 Series Technical Manual

1MRK 511 557-UEN Rev. A
strings, whereas "MU" and "01" are fixed and should not be changed. However, the MUx_4I_4U
function blocks will work correctly also with less restrictive values of SVId.
The SmplGrp parameter is not used in the PWC600 implementation, keep it at default value 0.
Within a MU1_4I_4U function block, the assignment of sampled values streams (4 currents, 4
voltages) is fixed, as provided by the MU.
13.7.6.2

Time synchronization

Sampled values received over the process bus are time stamped. For synchronizing the signal
processing in the IED to the incoming data stream, an external 1PPS signal shall be provided on the
PPS Rx port (X10) of the communication interface module. Accuracy shall be class T4 (±4 µs) or
better.
Preferably, a GPS based clock source is used as master for generating a station-wide 1PPS clock for
all merging units and receiving IEDs. This is particularly important when an IED may receive sampled
values from more than one MU. Only if any IED is connected to just one MU then the MU may be
used as clock master for the receiving IED(s).
The SynchMode parameter determines handling of the synchronization information in the
datastream:
• When set to "NoSynch" it will not check the SmpSynch flag.
• When set to "Operation" it will always check the SmpSynch flag.
• "Init" should not be used.
See TIMESYNCHGEN for further information on time synchronization.
13.7.6.3

Alarm signals

Each MU function block has five binary alarm signal outputs.
• MUDATA: Indicates when sample sequence needs to be realigned, that is, the application needs
to be restarted soon. The signal is raised for 2 seconds before the application is restarted.
• SYNCH: Indicates that the internal time synchronization quality is out of the set value from
parameter TIMESYNCHGEN.syncAccLevel ("1 μs", "4 μs" or "unspecified") and the parameter
TIMESYNCHGEN.AppSynch is set to "Synch". If TIMESYNCHGEN.AppSynch is set to
"NoSynch", the SYNCH output never goes high.
• SMPLT: Indicates that more than one sample has been lost or marked as invalid, overflown or
failed and the sample has thereafter been substituted.
• SYNMU: Indicates that the MU connected is not synchronized. Received from SmpSynch flag in
datastream. No IED setting affects this signal.
• TSTMD: Indicates that the MU connected is in "Test Mode". Received from Test flag in
datastream. No IED setting affects this signal.
Technical Manual
In case of communication problems, all analog outputs will be forced to 0.0.
Connect the binary output signals, except for TSTMD, to the BLKSYNSW input of
the SSCPOW function, for blocking controlled switching operations in case of
communication problems. See the section on Controlled Switching & Monitoring.
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Section 13
Station communication
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