Display and PIN

Messages used: Display · PIN

Status messages from the terminal

During a transaction, the terminal sends Display requests telling the ECR what is happening: waiting for card, waiting for PIN, connecting to the host and so on. Show them to the cashier.

• Expect them at any time during a transaction.
• Don't rely on their order, number or text: these can change with the terminal's software version and language.

PIN entry controlled by the ECR

In some special use cases, agreed with Aera, the ECR controls PIN entry itself.

1. The ECR sends a PIN request with:
   • the amount (RequestedAmount) and the brand name to show (AeDisplayBrand)
   • the card number or identifier (AdditionalInput)
   • AePINEnterMessage = PIN_FIRST_TRY
   • AePINSessionTimeout: how long the terminal waits for the next step, in milliseconds.
2. The customer enters the PIN. The terminal encrypts it and returns the encrypted PIN block.
3. The ECR checks the PIN with its own system.
4. Before AePINSessionTimeout runs out (counted from the PIN response), the ECR sends either:
   • a Display request with the result: TRANSACTION_APPROVED, TRANSACTION_DECLINED or TRANSACTION_ABORTED, or
   • if the PIN was wrong, a new PIN request with AePINEnterMessage = PIN_TRY_AGAIN or PIN_LAST_TRY.

The TRANSACTION_* display values work only together with a PIN request. You can't use them in any other flow.