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<a href="#"><span></span>→ Things merge examples</a>
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<li><a href="protocol-examples-mergeattributes.html">Merge Attributes</a></li>
<li><a href="protocol-examples-mergeattribute.html">Merge a single Attribute</a></li>
<li><a href="protocol-examples-mergethingdefinition.html">Merge a Definition</a></li>
<li><a href="protocol-examples-mergefeatures.html">Merge Features</a></li>
<li><a href="protocol-examples-mergefeature.html">Merge a single Feature</a></li>
<li><a href="protocol-examples-mergefeaturedefinition.html">Merge Feature Definition</a></li>
<li><a href="protocol-examples-mergeproperties.html">Merge Feature Properties</a></li>
<li><a href="protocol-examples-mergeproperty.html">Merge a single Property</a></li>
<li><a href="protocol-examples-mergedesiredproperties.html">Merge desired Feature Properties</a></li>
<li><a href="protocol-examples-mergedesiredproperty.html">Merge a single desired Property</a></li>
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<a href="#"><span></span>→ Policies examples</a>
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<li><a href="protocol-examples-policies-deletepolicy.html">Delete a Policy</a></li>
<li><a href="protocol-examples-policies-modifypolicy.html">Modify a Policy</a></li>
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<h1 class="post-title-main">Signal topics</h1>
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<p>The following pages and posts are tagged with <button type="button" style="cursor: default" class="btn btn-default navbar-btn">signal</button></p>
<table><thead><tr><th>Title</th><th>Type</th><th>Excerpt</th></tr></thead>
<tbody>
<tr><td><a href="basic-signals-announcement.html">Announcement</a></td>
<td><span class="label label-default">Page</span></td>
<td> Announcements are special signals which are published in order to announce something before it actually happens. For example, before an event is created and published, an announcement could signal that the event will happen soon. Announcements have the following characteristics: they are not persisted/appended into any data... </td>
</tr>
<tr><td><a href="basic-signals-command.html">Command</a></td>
<td><span class="label label-default">Page</span></td>
<td> Commands involve the need to change or retrieve something of a digital twin managed by Ditto or an actual device connected to Ditto. Commands always contain an identifier of the entity they address (e.g. a Thing ID). Modify Commands Commands which modify a digital twin or an actual... </td>
</tr>
<tr><td><a href="basic-signals-commandresponse.html">Command response</a></td>
<td><span class="label label-default">Page</span></td>
<td> CommandResponses are the answer to Commands and include information about whether the
intention of changing something via a ModifyCommand has worked or if there was an Error
instead.
The CommandResponse of QueryCommands contains the requested information.
</td>
</tr>
<tr><td><a href="basic-signals-errorresponse.html">Error response</a></td>
<td><span class="label label-default">Page</span></td>
<td> If an issued command or message could not be applied, an appropriate error response conveys this error information back to the issuer. Failure of a command or message can have various reasons, starting from missing permissions to internal server errors during processing of the command. The... </td>
</tr>
<tr><td><a href="basic-signals-event.html">Event</a></td>
<td><span class="label label-default">Page</span></td>
<td> Events report that something took place in a digital twin in Ditto. Important is the “past tense” here; it took already place (it was for example persisted into the data store) and cannot be reversed or stopped. Events are one of the centerpieces of Ditto: they are persisted/appended into... </td>
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<tr><td><a href="basic-signals.html">Signals</a></td>
<td><span class="label label-default">Page</span></td>
<td> Ditto has a concept called Signal which combines common functionality of Commands, Command Responses, Error Responses, Events and Announcements. Such common functionality is for example that all those have header fields in which they can be for example correlated to each other.... </td>
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