> For the complete documentation index, see [llms.txt](https://docs.videc.de/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.videc.de/acron-9.3/en/ac_admin/anlagenuebersicht/anlage/dienste_und_anwendungen/opc-ua-server.md).

# OPC UA-Server

To enable you to view ACRON measurement and service data, from your control system for example, in a dedicated view, or to display automated action information messages, ACRON delivers the data by way of a OPC UA server (ACOpcUA.EXE). This interface can be used by all OPC UA-compatible systems.

See also: <https://de.wikipedia.org/wiki/OPC\\_Unified\\_Architecture>

## Server

### Status

Status of OPC UA server

## Connection <a href="#verbindung" id="verbindung"></a>

### Server address

The name entered here must match the host or domain name of the computer on which the OPC UA Server is to run. This name is also used to verify the certificate when security is active at runtime.

### Port

TCP/IP port number to be used by the OPC UA Server

## Timing and intervals <a href="#zeitangaben-intervalle" id="zeitangaben-intervalle"></a>

### Time stamp in local time

Timestamps are displayed in local time, otherwise UTC is used.

### Refreshgh rate for process data

Process data is updated every n milliseconds (values from 200 to 6000 ms are allowed)

## Authentication <a href="#authentifizierung" id="authentifizierung"></a>

### Anonymous

Clients authenticate without user and password

### User

Username/password combinations that clients can use to authenticate themselves.

A maximum of 8 entries are possible, entries with empty password are permitted

#### Icons

|                                                        |                  |
| ------------------------------------------------------ | ---------------- |
| !\[]\(../../../../.gitbook/assets/action add2\_32.png) | Add a new user   |
| ![](/files/3NyKydc7tfWtPux3fIEI)                       | Delete the entry |

## Security policies <a href="#sicherheitsrichtlinien" id="sicherheitsrichtlinien"></a>

Any combination of security policies is allowed, but at least 1 must be selected.

If a digitally signed connection is selected, the corresponding [client certificates](#clientzertifikat) must be stored.

### None (insecure)

The connection is neither digitally signed nor encrypted.

Note

This method is insecure.

### Basic256Sha256

The communication is signed or encrypted using the Basic256Sha256 algorithm.

### Aes128Sha256RsaOaep

The communication is signed or encrypted using the Aes128Sha256RsaOaep algorithm.

## Server certificate <a href="#serverzertifikat" id="serverzertifikat"></a>

There are two different ways to select a certificate:

* Import a certificate from a certificate file

  Click the 'Import certificate' button and select a \*.pfx file.
* Create a self-signed certificate

  The certificate files are stored in the ACRON configuration path. A maximum of one certificate for the server can exist per plant.

Note

Self-signed certificates may provide only a limited level of security. For productive operation, it is recommended to use certificates issued by a trusted certification authority.

Click the 'Export certificate' button to save a self-signed certificate without the private key as a \*.der file on the desktop.

## Client certificate <a href="#clientzertifikat" id="clientzertifikat"></a>

Certificates used to verify the clients identity when connection signing is enabled (see "Security policies").

Client certificates that are to be trusted must be stored in the specified folder.


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