Event Description
Event = VarID + Value + Timestamp
VarID: It is internally managed by the system.
VarID is unique for 1 PLC.
User only manages the variable name.
Value: Event discrete value.
Timestamp: Time stamp in OPC DA format.
Event Data Format
Event data format is provided for information even if this structure is not accessed in system time stamping mode.
Each event time stamp entry is a 12 bytes block organized as follows:
|
Byte 0 |
||
|
Byte 1 |
||
|
Bit 7...0 |
Byte 2 |
|
Bit 15...8 |
Byte 3 |
||
|
|
Bit 7...0 |
Byte 4 |
Bit 15...8 |
Byte 5 |
||
Bit 23...16 |
Byte 6 |
||
Bit 31...24 |
Byte 7 |
||
|
Bit 7...0 |
Byte 8 |
|
Bit 15...8 |
Byte 9 |
||
Bit 23...16 |
Byte 10 |
||
|
Byte 11 |
Each parameter is detailed hereunder.
Value
Parameter
Bit 0 defines the value of the variable after change detection:
0: Falling edge
1: Rising edge
Event ID
Parameter
The variable management assigns a unique value to each time stamped event (including SOE_UNCERTAIN event).
DateAndTime
Parameter
Defines the date and time of the variable change detection.
The following table describes the DataAndTime
parameter format:
Attribute Name |
Type |
Description/Value |
Position |
---|---|---|---|
|
|
Number of seconds since midnight (00:00:00) 1970/01/01 (UTC time). (0...MAX) |
|
|
|
FRACT_SEC_0 (LSByte) |
B7-B0 |
FRACT_SEC_1 |
B15-B8 |
||
FRACT_SEC_2 (MSByte) |
B23-B16 (B23 = 1 for 1/2 s) |
The time format is defined according to IEC 61850-7-2 Edition 2.
Representation of the FractionOfSecond
parameter structure:
FRACT_SEC_2 (MSByte) |
FRACT_SEC_1 (2nd byte) |
FRACT_SEC_0 (LSByte) |
|||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
23 |
22 |
21 |
20 |
19 |
18 |
17 |
16 |
15 |
14 |
13 |
12 |
11 |
10 |
9 |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
TimeQuality
Parameter
The following table describes the TimeQuality
parameter format:
Attribute Name |
Type |
Description/Value |
---|---|---|
|
|
This bit is set to FALSE. |
|
|
Same meaning as I% (implicit variable) |
|
|
Same meaning as the I% (implicit
variable) |
|
|
Number of significant bits in the Minimum time interval is: 2* –n. In IEC norm, the
|
TimeAccuracy
is also used
to set specific values of TimeQuality
as described
in the following table:
|
Values |
Comments |
---|---|---|
Unspecified |
0xx11111 |
Used in case of time stamping detection cycle not periodic. |
Invalid |
0xx11110 |
Time invalid, used in case of buffer full. |
|
0xx11101 |
Used in case of I/O channel error detection. |
|
0xx11100 |
Used in case of synchronization of the values with the client (done by storing a virtual event with 16-ch discrete values inside the buffer). |
|
0xx11011 |
Used in case of external clock during synchronization (catch up mode). |
If several specific values are simultaneously detected,
the precedence of TimeAccuracy
specific values is:
TimeAccuracy
=IOChannelError
(highest priority)TimeAccuracy
= Invalid orTSInit
TimeAccuracy
=ClockInSync
TimeAccuracy
= Unspecified