Section 3
1MAC052634-MB D
Vendor-specific implementation
32
615/620 series ANSI
Communication Protocol Manual
Unread records left
This register shows how many unread event records still remain unread for the client in
question at a particular moment.
Time stamp registers
Time stamp is either in local time or UTC time. The time stamp alternative is selected with
a Modbus parameter.
Time stamp registers usually hold two data values in the high and low byte of the registers.
High byte value = RegisterValue DIV 256, Low byte value = RegisterValue MOD 256.
The Milliseconds register is an exception as it contains the milliseconds 0...999 coded as
such.
Event type
This register contains information to interpret the event data correctly.
Table 21:
Information contained by the 16 bit register
Event time stamp format bit 15
Event time stamp format.
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.
Bit
Meaning
Values
15
Event time
stamp format
0 = Local time
1 = UTC time
14
Time stamp
source
0 = Internal application
1 = Modbus stack
13
Clock not
synchronized
0 = Synchronized
1 = Time not synchronized
12
Clock failure
0 = Clock OK
1 = Clock failure
11
Reserved
0
10
Reserved
0
9
Reserved
0
8
Data object
ID type
0 = Modbus address
1 = UID data
7...0
Data value
identification
00000000 = One bit indication
00000010 = Two bit indication
00000100...
00001010 = Integer value
11111111 = reserved
00000001 = ACD indication
00000011 = SEC indadd data
00001001 = reserved
00001011...
