Node
The payment terms consist of a description (note) and the number of days before payment is due.
<cac:PaymentTerms>
<cbc:Note> </cbc:Note>
<cac:SettlementPeriod>
<cbc:DurationMeasure unitCode=" "> </cbc:DurationMeasure>
</cac:SettlementPeriod>
</cac:PaymentTerms>
In Isah
The number of days in the order message is checked against the number of days in PaymentTerm.TermOfPaym via Customer.PaymTermCode. They have to match, or the order will not be imported.
The sales order uses Customer.PaymTermCode from your Isah database.