OPC-UA Interface Guide (Press Emulator)

PrePress Plugin v4.11.6782.0, Copyright (c) 2024 Global Graphics Software. All rights reserved.

Overview

The PrePress Plugin allows you to work on files before it goes to the press.

When the Open Platform Communications (OPC) server in PrePress Plugin is enabled an OPC node tree is published. The nodes in this tree represent grouped areas of state and functionality.

Default address: opc.tcp://localhost:26842/spc-prepress

Certificates

Communication between OPC UA clients and servers require both parties to possess their own application certificate. To enable further communication each party must trust the opposing certificate. This trust can be established automatically, programmatically or manually depending on the application's configuration or implementation. The certificate for Pre-Press plugin can be found in %programdata%\Global Graphics Software Ltd\PrePress Plugin\App Certificates\certs should you need to copy it to the Trusted Peer Certificate folder. In this release it will be a Self Signed Certificate issued by and for Pre-Press plugin.

OPC Methods

Any methods listed in this documentation will include details about their required parameters (if any), and return value.

In the event of an error please see the application log file for more information.

OPC Client Library

The following documentation provides guidance on using the Traeger Industry Components GmbH OPC client library for software developers working with PrePress Plugin.

Configuring Custom Message Sizes

The default maximum message sizes used by OPC clients to communicate to the server are sufficient for most use cases. However, to ensure transfer of larger data packets (such as retrieving some job thumbnail images) it may be necessary to configure the OPC client with custom values.

For example:

	Client = new OpcClient();
	Client.Transport.MaxArrayLength = 1024 * 1024 * 50;
	Client.Transport.MaxBufferSize = 1024 * 1024 * 50;
	Client.Transport.MaxMessageSize = 1024 * 1024 * 50;
	Client.Transport.MaxStringLength = 1024 * 1024 * 50;

See here for more information.

Adjusting Communication Timeouts

OPC clients regularly verify the responsiveness of the connection to the OPC server. However, in certain circumstances where the system is under heavy load, maintaining a responsive connection might not always be possible. To mitigate potential issues under such conditions, it is recommended to increase the default communication timeouts.

The example below demonstrates how to adjust the default values:

	var defaultTimeOut = (int)TimeSpan.FromMinutes(10).TotalMilliseconds;
	Client = new OpcClient
	{
	    // Don't auto-disconnect - Dispose the client to explicitly disconnect.
	    DisconnectTimeout = int.MaxValue,
	    KeepAlive = { Interval = defaultTimeOut },
	    SessionTimeout = defaultTimeOut,
	    OperationTimeout = defaultTimeOut,
	    ReconnectTimeout = defaultTimeOut
	};

Please note that the provided examples serve as illustrations, and it's important to tailor the configuration to your specific requirements.

PrePressSet

The top-level set containing all available OPC nodes.

Immediately underneath this root-level node are a categorized collection of sub-nodes, each encapsulating a different area of behavior.

HotFolders

This node tree provides access to the hot folder functionality, enabling external systems to monitor their count, media assignments, and if they are enabled.

Details

These OPC nodes are fully populated to a consistent state when the OPC server starts, apart from hot folder nodes - These nodes are dynamically added and removed as hot folders are added and removed to/from the workflow.
(If there are already hot folders in the workflow, these will exist when the OPC server starts.)

Properties

PdfEditor

This node tree provides access to the selected PDF editor and the PDF arguments.

Properties

PrePressFolder

This node tree provides access to the PrePress folder functionality, to see the location and if it is enabled.

Properties

PrePressJobs

This node tree provides access to the jobs in the PrePress plugin.

Details

These OPC nodes are fully populated to a consistent state when the OPC server starts, apart from PrePress job nodes - These nodes are dynamically added and removed as PrePress jobs are added and removed to/from the workflow.
(If there are already PrePress jobs in the workflow, these will exist when the OPC server starts.)

Properties

SingleHotFolder

Describes the collection of nodes representing a single hot folder, positioned as a child of the 'HotFolder' node.

Properties

SingleJob

Describes the collection of nodes representing a single PrePress job, positioned as a child of the 'PrePressJobs' node.

Properties

WorkFlowFolder

This node tree provides access to the work flow folder functionality, the user can see the location of the folder and if it is enabled.

Properties