OPOS Weight Scale not working

Hello,

We have purchased a "Mettler Toledo Ariva-S" weight scale which supports OPOS. Next, we did all settings to get it work with Microsoft Dynamics AX 2012 POS: The weight scale is correctly detected by the POS application. But it fails to read weight from POS (with the OPOS admin app provided by Mettler the reading works fine)?

Have anyone already used this kind of weight scale? Had you ever succeeded to get an OPOS compatible weight scale work with AX2012?

Best regards,

Mohamed Amine