Mapping Of Data Types - Siemens SIMATIC ET 200AL System Manual

9.1.7

Mapping of data types

SIMATIC and OPC UA data types
SIMATIC data types do not always correspond with OPC UA data types.
S7-1500 CPUs provide SIMATIC tags (with SIMATIC data types) to their own OPC UA server as
OPC UA data types. OPC UA clients can then access these tags with OPC UA data types via the
server interface.
A client can read the attribute "DataType" from such a tag and reconstruct the original data
type in SIMATIC.
Example
A tag has the SIMATIC data type "COUNTER". You read COUNTER → UInt16 in the table. You
now know that you do not need to convert; the COUNTER value is sent over the line as a
UInt16 data type.
The client detects from the attribute "DataType" that the tag is actually the SIMATIC data type
"COUNTER". With this knowledge, the client reconstructs the data type.
Table 9- 1
SIMATIC data type
BOOL
BYTE
WORD
DWORD
LWORD
SINT
INT
DINT
LINT
USINT
UINT
UDINT
ULINT
REAL
LREAL
S5TIME
TIME
LTIME
Communication
Function Manual, 05/2021, A5E03735815-AJ
SIMATIC and OPC UA data types
OPC UA communication
9.1 What you need to know about OPC UA
OPC UA data type
Boolean
BYTE
→ Byte
WORD
→ UInt16
DWORD
→ UInt32
LWORD
→ UInt64
SByte
Int16
Int32
Int64
Byte
UInt16
UInt32
UInt64
Float
Double
S5TIME
→ UInt16
TIME
→ Int32
LTIME
→ Int64
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