Siemens SIMATIC ET 200AL - Mapping of Data Types

OPC UA communication
9.1 What you need to know about OPC UA
Communication
136 Function Manual, 12/2017, A5E03735815-AF
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 so that OPC UA clients can access these tags over the server
interface with OPC UA data types.
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 can see from the "Datatype" attribute that it is actually a COUNTER data type and
can reconstruct it in this knowledge.
Table 9- 1 SIMATIC and OPC UA data types
SIMATIC data type
OPC UA data type
BOOL
Boolean
BYTE BYTE
→ Byte
WORD WORD
→ UInt16
DWORD DWORD
→ UInt32
LWORD LWORD
→ UInt64
SINT
SByte
INT
Int16
DINT
Int32
LINT
Int64
USINT
Byte
UINT
UInt16
UDINT
UInt32
ULINT
UInt64
REAL
Float
LREAL
Double
S5TIME S5TIME
→ UInt16
TIME TIME
→ Int32