HARTING
MICA OPC-UA Gateway
–
User Manual
12
peraMIC GmbH & Co. KG
6
Executor
The
Executor
is a small tool to easily read data from or write data to devices which are
connected to the OPC UA Gateway. You can also use the
Execute
operation to run OPC UA
commands on an OPC UA node connected to the MICA.
To execute an OPC UA query you must provide 5 properties:
•
The
Device URL
of the device you want to connect to. You can either choose an
active device from the section Devices or enter the address of an OPC UA device. If
your connection requires another port than the default port 4840 you must add
the port to the connection string as shown in the example.
•
The
Identifier
of the node in the address space of an OPC UA device. If you have
selected a device as the
Device URL
you are also able to choose from the defined
fields of that device.
•
The
Operation
either
READ
or
WRITE
or
EXECUTE
.
•
The
Namespace
index of a node in an OPC UA server.
•
The
Type
of the identifier. It can be a numeric value or a string. This property will
only be visible if no field was selected as the
Identifier
.
Run the Executor by clicking the
button.
6.1
Error messages
When executing an OPC UA query the device may respond with error messages. The most
important ones will be explained in this section. For a complete list of error messages,
please check the documentation that came with your OPC UA device or the OPC UA
standard. OPC UA error messages will appear on the bottom of the screen.
The first part is telling you what operation has failed, i.e.
Failed to execute read operation.
The second part tells you more information on what caused the problem. The following list
shows the main mistakes that can lead to an error:
•
Cannot get value for 'Identifier'
o
This message will appear if the OPC UA Gateway was not able to establish
a connection to the given
Device URL
.
•
Cannot get value for 'Identifier': INVALID PARAMETER
o
This message will appear if the OPC UA Gateway was not able to get a
value for the given
Identifier
.
•
Scheme seems invalid! The only supported scheme is 'tcp'
o
This message will appear if you have used an unsupported scheme in the
Device URL
.
