Siemens SIMATIC S7-1500 Function Manual page 173

OPC UA communication
9.3 Using the S7-1500 as an OPC UA server
Handling of the attribute in the server
The "AccessLevelEx" attribute is only available in the OPC UA server. The attribute is not
present in a node set file (XML export file).
However, the attribute "AccessLevel", which is exported, includes the information from
"AccessLevelEx", see next section.
Export
During XML export of the standard SIMATIC server interface, the server sets the
"AccessLevel" attribute, which was expanded to 32 bits in V1.04 compared to V1.03, to the
value of the "AccessLevelEx" attribute.
Import
When importing a node set file (e.g. from an export of a server interface), the S7-1500 CPU
sets the attribute "AccessLevelEx" according to its own estimate of the consistency of the
imported data type, see next section. The imported value is ignored.
Consistency of data types at the server interface
The consistency of tags ("atomicity" in the language usage of OPC UA) within a program
cycle of an S7-1500 CPU is ensured at the nodes of the server interface for the following
data types:
● BOOL, BYTE, WORD, DWORD, LWORD
● SINT, INT, LINT, DINT, USINT, UINT, ULINT, UDINT
● REAL, LREAL
● DATE, LDT, TIME, LTIME, TIME_OF_DAY, LTIME_OF_DAY, S5TIME
● CHAR, WCHAR
● System data types and hardware data types that are based on the above-mentioned data
types are also consistent.
Example: HW_ANY, derived from UINT (UInt16).
Tip: If you browse in the address space of the S7-1500 CPU (e.g. with the OPC UA Client
UaExpert), you can find the consistent data types under Types > BaseDataType >
Enumeration/Number/String.
Tags of the following data types are not consistent ("nonatomic" in the language usage of
OPC UA):
● SIMATIC structures are generally not consistent. This means that all tags which, for
example, have unknown structures or a UDT data type are not consistent.
● System data types such as DTL, IEC_Counter, IEC_TIMER, etc. are data types that are
derived from structures.
Tip: If you browse in the address space of the S7-1500 CPU (e.g. with the OPC UA Client
UaExpert), you can find data types based on structures under Types > BaseDataType >
Structure.
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Function Manual, 11/2019, A5E03735815-AH
Communication