Siemens CP 1243-1 - Read Cycle

Configuration
4.10 Data points
CP 1243-1
96 Operating Instructions, 04/2017, C79000-G8976-C365-03
Status identifiers with the DNP3 protocol
The status IDs correspond to the following elements of the specification:
OBJECT FLAGS - DNP3 Specification, Volume 6, Data Object Library - Part 1
Table 4- 5 Bit assignment of the status byte
Bit
7
6
5
4
3
2
1
0
Flag name
- - - LOCAL_
FORCED
DISCONTI
NUITY
OVER_
RANGE
RESTART ONLINE
Meaning
- - - Local opera-
tor control
Counted
value over-
flow before
reading the
value
Limit value of
the analog
prepro-
cessing over-
shot /
undershot
Value not yet
updated after
start
Value is valid
Bit status
(always
0)
(always
0)
(always
0)
1 1 1 1 1
Status identifiers with the IEC protocol
The status IDs correspond to the following elements of the specification:
Quality descriptor - IEC 60870 Part 5-101
Table 4- 6 Bit assignment of the status byte
Bit
7
6
5
4
3
2
1
0
Flag name
- - SB
substituted
- CY
carry
OV
overflow
NT
not topical
IV
invalid
Meaning
- - Substitute
value
- Counted
value over-
flow before
reading the
value
Value range
exceeded,
analog value
Value not
updated
Value is valid
Bit status
(always
0)
(always
0)
1
(always
0)
1 1 1 0
4.10.6
Read cycle
Priority of the data points
The cyclic reading of the values of input data points from their assigned PLC tags on the
CPU can be prioritized.
Less important input data points do not need to be read in every CPU scan cycle. Important
input data points, on the other hand, can be prioritized for updating in every CPU scan cycle.