ABB Relion 620 Series Protocol Manual page 58

Section 3
Vendor-specific implementation
52
Bit Meaning
9 Reserved
8 Data object
ID type
7...0 Data value
identification
Event time stamp format bit 15
The time stamp format can be selected with a Modbus parameter via the LHMI,
WHMI or the Parameter Setting tool.
Event time stamp source bit 14
The time stamp can be generated by the IED application (accurate time) or by
Modbus. If generated by Modbus, the change values are detected by the Modbus
background scan task. Since there is a latency time between the value change and the
time when Modbus detects the change, the time stamp is not accurate in this case.
Clock not synchronized bit 13
The quality information bit is set in the IED's real-time clock if the IED has not been
synchronized.
Clock failure bit 12
The quality information bit is set in the IED's real-time clock if the clock has a severe
failure. Do not rely on this time stamp.
Data object ID bit 8
The coding alternatives of the data object ID registers 1 and 2 are the Modbus address
or UID. The coding alternatives cannot occur simultaneously in the IED but are
selected and configured at the system setup phase. The default setting is "Modbus
address".
The UID code is 32 bits wide and occupies both registers 9259 and 9260. The word
order is high/low. The UID code refers to the functional design of the IED platform in
which the object resides. Shortly, it means that the UID code is equal in all the
platform IEDs in which the same functional design and the same Modbus object is
used.
While UID is supported for backwards compatibility, it is not
unambiguous for all indication objects.
Values
0
0 = Modbus address
00000000 = One bit indication
00000010 = Two bit indication
00000100...
00001010 = Integer value
11111111 = reserved
1MRS757645 B
1 = UID data
00000001 = ACD indication
00000011 = SEC indication+add data
00001001 = reserved
00001011...
620 series
Communication Protocol Manual