Simply
The module via an internal mechanism to Prestashop, on each product update saves the event in the database.
This update can be an update of stock, price, description etc. Once you click “Save” the information is stored for later use.
When the update script is launched, then it processes the “Event Log”, all modified products since last time are sent back to Amazon.
In Detail
The Amazon module uses the technique of synchronization by Hooks described in a ticket on the Prestashop blog here:
http://www.prestashop.com/blog/fr/la_synchronisation_via_les_hooks_ebay_par_fabien_serny/
And in the official Prestashop documentation here:
http://doc.prestashop.com/display/PS14/Synchronization+via+Hooks
(Note that the evoked version of Prestashop does not matter in this case, this operation affects all versions)
By default, the module synchronizes your offers, that is, it sends the quantities and prices and only for items that have been modified.
The operating principle is the same as that of eBay module, except that the Amazon module will only do the update a posteriori. Indeed, for each update of a product on eBay Module, it connects to eBay and transmits the information, the product or offer update, but it is not compatible with the operating mechanism of the Amazon marketplace, which requires sending batch updates.
When updating an item, the Amazon module saves this update in a table, it is called “Logging”.
Then, when you will request the module for an export, either by using the interactive menu “Catalog > Amazon” or by a scheduled task, the module lists all the log entries and sends the information to Amazon, the module sends a “feed”.
While the module does not receive an “acknowledgment” from Amazon, it maintains information in the log. When it is received, the log entry is deleted. So you have the certainty that your data on Amazon will be constantly updated.
Our clients sometimes use external software to update inventory/stock, POS management software etc. In this case the customer must ensure that the software is fully compatible with Prestashop and that it effectively triggers the necessary Hook to its proper functioning. If you are concerned, give a link of this page to your technical provider.
Also, if you want to ensure the smooth operation of the module, you must then simply go to a product sheet and modify the quantity of the product, a new entry will appear in the log, you will see in the “Tools” tab of the module configuration, the queue has been incremented.
