What version of Purchase Orders are you using? I ask because Adagio PurchaseOrders version 8.1C and later require integration with AP, so it would be interesting to know if you are using a Purchase Orders version older than this, or if you simply have a set of unused AP data so that your Purchase Orders will work.

In the Adagio PurchaseOrders company profile, on the System Options tab, there settings for what value is used to update the IC Most Recent Cost and other costs. One of the settings is 'Do not update', so that changed recent costs on posted purchase orders to not change values on Inventory items. Is this what you were looking for?

If your purchase orders and receipts have non-zero costs on item details, I do not believe you can prevent transaction costs from flowing to IC Transaction History, nor can you prevent Total Costs from being updated on the items. I suspect you would have to ensure that all IC items have all costs equal to zero, if all you are doing is tracking quantities and not costs.

You may need to get your Adagio consultant involved, depending on how you have your Purchase Orders program configured.