Configuration
4.18 Data points
CP 1243-8 IRC
Operating Instructions, 02/2018, C79000-G8976-C385-03
141
Time stamp of the ST7 frames
The values of the data points are transferred by the communications moduel with a time
stamp, see also section Creating telecontrol connections for the ST7 communication
(Page 122), subsection "Connections to redundant control centers and other properties".
Format of the time stamp
The ST7 time stamp is coded in BCD format. The exception is the half byte (nibble) with the
time status.
The structure of 8 bytes is assigned as follows:
Table 4- 5
Assignment of the structure of the time stamp
Byte no.
Content
High nibble
Low nibble
0
Year * 10
Year * 1
1
Month * 10
Month * 1
2
Day * 10
Day * 1
3
Hour * 10
Hour * 1
4
Minute * 10
Minute * 1
5
Second * 10
Second * 1
6
Millisecond * 100
Millisecond * 10
7
Millisecond * 1
Time status
Table 4- 6
The assignment of the half byte "time status" (low nibble of byte 7)
Bit No.
Value
Meaning
0
0
Time is invalid
1
Time is valid
1
0
Standard time
1
Daylight saving time
2
Not used
3
Not used
4.18.4
Status IDs of the data points
Status identifier (DNP3, IEC)
With the DNP3 and IEC protocols status identifiers of the values are output. The status
identifiers of the data points listed in the following tables are transferred along with the value
in each frame to the communications partner. They can be evaluated by the communications
partner.
The entries in the table row "Significance" relate to the entry in the table row "Bit status".