Understanding which objects and fields are used for Payment Connectors

targetx_payment__Confirmation_Code__c - Where the Payment Confirmation code is saved on successful payments
targetx_payment__Confirmation_Source__c - not used by nelnet
targetx_payment__Confirmation_Type__c - In Nelnet Hosted Payment Pages, this will be Success or Failure
targetx_payment__Confirmed_Amount__c - Payment amount confirmed from the Payment Gateway (nelnet in this case)
targetx_payment__Contact__c - related contact
targetx_payment__Expected_Amount__c - Deprecated field
targetx_payment__Gateway_Payment_Ref__c - ID issued by Payment Gateway. For nelnet this is paymentId
targetx_payment__Item_Cost_Total__c - Summation of cost from Purchase Item object
targetx_payment__Payment_Connector__c - Which Payment Connector was used when creating this record
targetx_payment__Payment_Method__c - Credit Card and type, or ACH
targetx_payment__UserSessionID__c - Salesforce session established with purchaser
targetx_payment__portalSessionNumber__c - not used by nelnet
targetx_payment__portalTicketNumber__c - not used by nelnet
targetx_payment__Relevant_ID__c - (optional) Salesforce record related to this payment other than the contact
targetx_payment__Total_Due__c - Total amount due. Compare this against Confirmed Amount to be sure payment is complete
targetx_payment__type__c - (optional) descriptor text
targetx_payment__Vendor_Apex_Reference__c - stores the redirect url used after the user completes the payment.

targetx_payment__Cost_Per__c - the cost per each item purchased
targetx_payment__Item_Code__c - inventory id # of the item being purchased
targetx_payment__Item_Number__c - the number of the object in the shopping cart. i.e. the first item in the cart is item 1
targetx_payment__Line_Total__c - the total amount of the items ordered multiplied by the number of items ordered
(targetx_payment__Cost_Per__c * targetx_payment__Quantity__c)
targetx_payment__Quantity__c - The number of items ordered.
targetx_payment__Relevant_ID__c - salesforce ID# of the item ordered
targetx_payment__Transaction__c - transaction number, used for tracking the purchase