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

OPC UA communication
9.1 What you need to know about OPC UA
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 data type
BOOL
BYTE
WORD
DWORD
LWORD
SINT
INT
DINT
LINT
USINT
UINT
UDINT
ULINT
REAL
LREAL
S5TIME
TIME
136
SIMATIC and OPC UA data types
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
Function Manual, 12/2017, A5E03735815-AF
Communication