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2 PROFINET IO in SIPROTEC
2.8 Acyclic Reading and Writing of Data
47
SIPROTEC 4, Communication Module PROFINET IO, Communication Profile
C53000-L1840-C360-1, Edition 08.2012
2.8.2
Reading Unit IDs of Measured Values, Statistic Values, and Metered Values
An acyclic read telegram is defined for reading units and unit multipliers. The order of the values in the telegram
corresponds to the order of the values in the IO module.
Figure 2-23
Acyclic Data Telegram, Reading Unit IDs
Number of Values
•
IO module for measured values: 6 or 12
•
IO module for metered values: 4
•
IO module for statistic values: 3 or 6
Unit ID #1 through Unit ID #n
The telegram always only contains as many unit IDs as entered in the byte
Number of values
. This also
determines the length of the telegram.
The definition of the unit IDs is described in Chapter 2.3.7.
NOTE
For metered values:
After having set a metered value, this value is immediately applied in the SIPROTEC device and shown on the
display. Updating via PROFINET IO is only initiated with the next restore cycle.
The range of value for setting metered values is 0 to 7FFFFFFFH. When setting a greater value in the telegram,
the most significant bit (MSB) is automatically set to 0 on the EN100 and the value resulting thereof is
transmitted to the SIPROTEC device.
Example: 9234ABC6H is entered in the telegram; 1234ABC6H is set.
Number of values
Unit ID #1
(Unit16)
Unit ID #n
(Unit16)
Byte offset = 0
Start offset = 2
Start offset = 4
Start offset = n * 2
Max. end offset = (n * 2) + 1
...
Reserved = 0
Byte offset = 1
com_profinet-io_profile_us.book Page 47 Friday, August 17, 2012 1:40 PM