Generally we recommend using the "Send to Terminal" button in Salesforce, in order to send a transaction amount to the terminal and keep Salesforce updated.
Starting with Chargent Terminal v1.34, transactions that originate on the Chargent Terminal will get sync'd back to Salesforce. If you start with the terminal instead of Salesforce, however, you will need to associate those records in Salesforce with the correct customer.
To do so navigate to Unlinked Chargent Terminal Transactions.
1. Set your search criteria on the left
2. Select the object you are associating the records with (keep in mind you need to have the field in the page layout to create the relationship)
3. Click the Query button on the bottom.
From the Unlinked Transaction click the drop down box and select Link Transaction.
1. Associate the Chargent Order
2. Click Save