dataPARC PARCserver
.NET AGENT
Overview
The OPC-UA connector enables Seeq to access data from DataPARC PARCserver. Note that the OPC-UA connector provides connectivity to a variety of historical data via the OPC Foundation's standard Unified Architecture protocol.
Prerequisites
Server certificates
OPC-UA uses TLS for security - both a client (the connector) and a server (the historian) have certificates that must be trusted by the other for the connector to function.
When the connector attempts to open a communication channel with a historian, it sends its certificate to the historian, which then checks if it trusts the connector’s certificate. Similarly, the historian will send the connector its certificate, and the connector will check if it trusts the historian’s certificates. Each program checks the received certificate against those it trusts, and refuses the connection if it doesn’t find a match. This process is known as a handshake.
A simple way to accomplish this trust between the connector and the historian is to place the historian’s certificate into the connector’s trusted certificates folder, and place the connector’s certificate into the historian’s trusted certificates folder.
Connector certificate
The OPC-UA connector is configured to store certificates within the Seeq data folder at keys/opc-ua. There, you’ll find three subfolders (client, trusted, rejected) which are generated the first time the connector starts up. The connector’s certificate can be found at keys/opc-ua/client/certs. The historian’s certificate can be placed in keys/opc-ua/trusted (and may show up in keys/opc-ua/rejected if an attempt to connect was made).
Configuration
This is an example configuration template that is displayed in the Additional Configuration box that appears when you click Configure for an existing datasource (or if a new datasource is being created, in the Create new datasource connection modal that appears after clicking Add Datasource) on the Datasources administration page.
{
"Username": "<user here>",
"Password": "<password here>",
"ServerType": "DATAPARC",
"URL": "opc.tcp://HOSTNAME:51235/Capstone/OPCUAServer",
"ExcludedObjects": [],
"IncludeSignalTypeDefinitions": [
"CapstoneDataItemStringType",
"CapstoneAnalogItemType"
],
"MaxNodesPerServerRequest": 35000,
"RootNodeIds": [
"ns=4;i=7020"
],
"CreateAssetTree": true,
"VerboseLogging": false,
"LogSamples": false
}DataPARC PARCserver Historian Additional Configuration
Property Name | Default Value | Data Type | Description |
|---|---|---|---|
|
| String | The server URL field must be of the format The default port number for PARCserver is 51235, but may differ at your site. The default path is |
| null | String | This is the user name of a user that has access to the database. Note that the OPC-UA connector can connect to a server using (in order of precedence) a username and password or as an anonymous user. |
| null | String/SecretFile | This is the password of a user that has access to the database. It is recommended to leverage a Secrets File to store this information. Note that the OPC-UA connector can connect to a server using (in order of precedence) a username and password or as an anonymous user. |
ServerType | DATAPARC | String | This string lets the connector know how to index the datasource and should be set to |
ExcludedObjects | empty array | Array[String] | A list of objects that should be ignored from indexing. NOTE: ignoring an object will also ignore all children of that object. |
IncludeSignalTypeDefinitions | empty array | Array[String] | The default datatypes that PARCserver uses for tags are |
MaxNodesPerServerResquest | 35000 | Integer | This parameter limits the number of nodes requested at a time during indexing. If you are noticing time out issues during indexing, you can lower this value. |
RootNodeIds | empty array | Array[String] | If you are only interested in tag values this should be set to |
CreateAssetTree | true | Boolean | Determines whether the connection should generate an asset tree. If you have a very flat (thousands of tags to one asset) this could result in performance issues and should be set to false. |
VerboseLogging | false | Boolean | Turns on verbose logging for troubleshooting |
LogSamples | false | Boolean | NOTE: This should only be set to true while actively debugging data issues. This will cause a large increase in log messages and log file size and decreased performance. Will log all requested samples to the log file. |
Known Issues
There are no known issues for the dataPARC PARCserver connector via OPC-UA. Please report any issues you find to our support portal.
Troubleshooting
Verify with an external client
Use an external OPC-UA client (such as this free OPC-UA Client from Integration Objects) to connect to the historian server and confirm that it is running properly.
Known OPC-UA Errors
If the connector fails to pull in data from a signal with the error “Unexpected Error Processing Response”, try setting the configuration field MaxResultsPerRequest to a lower number. OPC-UA applications typically limit the size of messages sent between client and server.
If the connector tries to pull in data from multiple signals concurrently and fails with the error “BadInternalError”, try setting the configuration field MaxConcurrentRequests to 1.
If the connector fails to connect to a server with a “BadIdentityTokenInvalid” or “BadUserAccessDenied” error, make sure the username and password set in the configuration file match a user identity on the OPC-UA server. Alternatively, try setting the Username and Password fields in the configuration file to equal null, which can enable the connector to try a different authentication method.
If you are running into other issues with connecting to or access data from Siemens PCS7 Process Historian, view our guide for troubleshooting datasource issues.
Performance considerations
View our guide on optimizing datasource performance for general guidance.