<?xml version="1.0" encoding="utf-8"?>
<ManualTopic ID="/baanerp/da/onlinemanual/000018" xml:lang="en">
	<Header>
		<Title xmlns:HTML="http://www.w3.org/TR/REC-html40">Description of the subscription mechanism</Title>
		<Keyword ContextSensitive="No"><Level1>Exchange multisite control</Level1>
		</Keyword>
	</Header>
	<GeneralSection><Paragraph class="Default">When an <Link href="/baanerp/da/glossary/glossary#000031" role="glossary">exchange link</Link> between the <Link href="/baanerp/da/glossary/glossary#000037" role="glossary">target run</Link> and <Link href="/baanerp/da/glossary/glossary#000026" role="glossary">source batch</Link> is defined and activated, a <Link href="/baanerp/da/glossary/glossary#000039" role="glossary">subscription</Link> is automatically created by ERP LN and stored at the source site.</Paragraph>
		<Paragraph class="Default">An exchange of data is only possible if an active exchange link is available at the target site and the subscription is available at the source site.</Paragraph>
		<Figure space-and-orientation="indented-estimated"><HTML:IMG height="256" width="481" SRC="../images/tr_graph_000018.gif" path="/enterpriseserver/add-ons/da/onlinemanual" btb-count="1" btb-count2="1" btb-image-name="tr_graph_000018.gif" btb-source-path="C:\SVN\docnl\Technology\EnterpriseServer~8.5\EnterpriseServer" btb-image-path="/enterpriseserver/add-ons/da/images/tr_graph_000018.gif" ID="IDAO1V5B" alt="[...]" xmlns:HTML="http://www.w3.org/TR/REC-html40"/></Figure>
		<Paragraph class="Default">A subscribe message is sent to the source site when an exchange link is activated at the target site. The source checks and stores the subscription to make sure that it is correct and complete. From that moment the target site will be notified when the batch at the source site has run.</Paragraph>
		<Paragraph class="Default">An unsubscribe message is sent to the source site when a exchange link is deactivated at the target site. The status of the link is set to inactive at both sites, and the <Link href="/baanerp/da/glossary/glossary#000002" role="glossary">batch</Link> and <Link href="/baanerp/da/glossary/glossary#000032" role="glossary">table relation</Link> that would have been imported are deleted. The <Link href="/baanerp/da/glossary/glossary#000039" role="glossary">subscription</Link> will also be removed at the source site.</Paragraph>
		<Paragraph class="Default">A subscription destroyed message is sent to the target site when an source batch, or <Link href="/baanerp/da/glossary/glossary#000025" role="glossary">source exchange scheme</Link> is deleted at the source site. The subscriptions are also deleted. The exchange link to the source batch will be deactivated and receives the status inactive at the source and target sites.</Paragraph>
		<Note><SectionTitle>
                                 Note
                              </SectionTitle>
			<List><ListItem>An exchange link can only be deleted if it has the status inactive at both sites.</ListItem>
				<ListItem>The subscription will be deleted if the exchange link is deactivated.</ListItem>
			</List>
		</Note>
	</GeneralSection>
	<RelatedTopics><SectionTitle>
                              Related topics
                           </SectionTitle>
		<RelTopic><Link href="/baanerp/da/onlinemanual/000001" role="manual">Introduction to the Exchange module</Link>
		</RelTopic>
		<RelTopic><Link href="/baanerp/da/onlinemanual/000005" role="manual">Introduction to multisite control</Link>
		</RelTopic>
		<RelTopic><Link href="/baanerp/da/onlinemanual/000017" role="manual">To use exchange links</Link>
		</RelTopic>
	</RelatedTopics>
</ManualTopic>
