OPC UA Client

7 min

Note: This driver will be deprecated in a future release. We recommend using OPC UA Client Advanced.

Review the following information for setting up and configuring the OPC UA Client.

Belden Horizon Data Operations Compatible Series

Compatibility parameter	Compatible items
Driver type	Ethernet
Validated devices/series	Used to subscribe data from OPC UA servers. Only sends a message to the broker if the value changes at the server level. Subscription interval is defined at the driver level and does not have a polling interval at the tag level.

Note: The OPC UA client does not connect to the server with the Basic256Sha256-SE security policy.

Supported Servers

OPC UA Client

It provides better performance compared to other OPC UA Clients.
OPC UA Client with new design supports both poll and subscription mode.

Set up the PLC Device in Belden Horizon Data Operations DeviceHub

Configure the following parameters when you Connect a Device with this driver. Update default values to the specific setup of your device.

Parameter	Value
Type	OPC UA
Driver	OPC UA Client
Network Address	The device IP address
Network Port	4840
Certificate	Auto-generated
Private Key	Auto-generated

Configure the List of Registers

Browse for tags to add to this FreeTag device. See Add Tags to learn more.

Alternatively, when you Add Tags, for Register Name map the OPC server tags to the client using this format, where the semicolon is significant: ns=1;s=tagname.

Example: ns=2;s=Demo.Static.Scalar.Boolean

The following data types are supported:

int32
bool
sbyte
byte
int16
uint16
int32
uint32
int64
uint64
float32
float64
string
dump
desc

Refer to the following tag parameters.

Tag Parameters

Name: Enter a name based on this format: ns=1;s=tagname.
- Example: ns=2;s=Demo.Static.Scalar.Boolean
Value Type: Select a data type from the drop-down list.
Tag Name: Enter a name for the tag.
Description (Optional): Enter a description for the tag.
Tag Formula: Enter a formula for the tag to process the generated data. Two variables are permitted: value (current tag value) and timestamp (current tag UNIX time in milliseconds). The following math functions are available:
- sin
- cos
- sqrt
- tan
- power: power(x) performs the operation 10^x.
- log: log(x) is the natural logarithm (the logarithm is in base e).
- exp: exp(x) performs the operation e^x.
Only Publish on Change of Value: Select the checkbox to customize NATS messages to be published only when the value parameter changes from a previous value to a new one. Change of Value only applies to boolean, numeric (such as int or float), and simple string data types. It does not apply to complex types, such as JSON or array. Poll-once topics will not be affected by Change of Value settings. These topics will still only see a single message.
Meta Data: Metadata summarizes basic information about data. This feature allows you to define key-value pair data for the device output payload later on. It can then be used to find, use, and reuse particular instances of data.

Note: If you use special characters in meta data key names, the special characters are replaced with underscore characters in the payload. This can cause two key names to be combined into one. For example, configuring the key names a**b and a&&b will cause only one key name to be created (a__b).