Display

Message category	Class	Direction
`Display`	Device	Both

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Used in these guides
Connect your ECR · Implement the payment flow · Make a payment · Add optional features · Display and PIN · Test and get approved

Display notifications are sent by the terminal to the ECR, or the other way around, to inform about the status during the processing of transactions.

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Expect status messages at any time
Display requests to the ECR (Device = CashierDisplay) can arrive 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.

Example request and response

display

All fields

Example request - terminal to ECR during transaction processing

{
  "SaleToPOIRequest": {
    "MessageHeader": {
      "MessageCategory": "Display",
      "MessageClass": "Device",
      "MessageType": "Request",
      "POIID": "AT12345",
      "ProtocolVersion": "3.1",
      "SaleID": "ECR123",
      "ServiceID": "1",
      "DeviceID" : "3"
    },
    "DisplayRequest": {
      "DisplayOutput": [
        {
          "OutputContent": {
            "PredefinedContent": {
              "ReferenceID": "WAITING_FOR_CARD"
            },
            "OutputFormat": "MessageRef"
          },
          "Device": "CashierDisplay",
          "InfoQualify": "Status",
          "ResponseRequiredFlag": false
        }
      ]
    }
  }
}

Example request - ECR to terminal

{
  "SaleToPOIRequest": {
    "MessageHeader": {
      "MessageCategory": "Display",
      "MessageClass": "Device",
      "MessageType": "Request",
      "POIID": "AT12345",
      "ProtocolVersion": "3.1",
      "SaleID": "ECR123",
      "DeviceID" : "3"
    },
    "DisplayRequest": {
      "DisplayOutput": [
        {
          "OutputContent": {
            "PredefinedContent": {
              "ReferenceID": "TRANSACTION_APPROVED"
            },
            "OutputFormat": "MessageRef"
          },
          "Device": "CustomerDisplay",
          "InfoQualify": "Display",
          "ResponseRequiredFlag": true
        }
      ]
    }
  }
}

Field	Required	Description
`DisplayRequest`	Required	Contains the fields below
↳ `DisplayOutput`	Required	Contains the fields below
↳ `OutputContent`	Required	Contains the fields below
↳ `PredefinedContent`		Contains the fields below
↳ `ReferenceID`	Required	Enum. See table below for possible values
↳ `OutputFormat`	Required	Enum: MessageRef
↳ `Device`	Required	Enum: CashierDisplay, CustomerDisplay 'CashierDisplay' is used for messages to be displayed on the ECR screen. 'CustomerDisplay' is used for messages to be displayed on the terminal screen.
↳ `InfoQualify`	Required	Enum: Status, Display. 'Status' is used in DisplayRequests from terminal that informs ECR about the state the terminal is in 'Display' is used for DisplayRequests from ECR to terminal that shows a specific screen on the terminal display.
↳ `ResponseRequiredFlag`	Required	True or False. Whether a response is required or not. Must be set to True when sending DisplayRequest from ECR to terminal.

Example response - terminal to ECR

{
  "MessageHeader": {
    "MessageCategory": "Display",
    "MessageClass": "Device",
    "MessageType": "Response",
    "POIID": "AT12345",
    "ProtocolVersion": "3.1",
    "SaleID": "ECR123",
    "DeviceID": "3"
  },
  "DisplayResponse": {
    "OutputResult": [
      {
        "Device": "CustomerDisplay",
        "InfoQualify": "Status",
        "Response": {
          "Result": "Success"
        }
      }
    ]
  }
}

Field	Required	Description
`DisplayResponse`	Required	Contains the fields below
↳ `OutputResult`	Required	Contains the fields below
↳ `Device`	Required	Copied from request
↳ `InfoQualify`	Required	Copied from request
↳ `Response`	Required	Contains the fields below
↳ `Result`	Required	Enum: Success, Failure
↳ `ErrorCondition`	Optional	Enum: NotAllowed

ReferenceID values

ReferenceID	Description	Sent from
WAITING_FOR_CARD	A transaction has been initiated and the terminal is waiting for a card	Terminal
WAITING_FOR_PIN	The terminal is waiting for the cardholder to enter the PIN	Terminal
WAITING_FOR_CUSTOMER_ACTION	The terminal is waiting for some action from the customer, such as confirming a choice or inputting a value.	Terminal
HOST_CONNECT	Terminal is connecting to transaction gateway	Terminal
HOST_SEND	Terminal is sending transaction request	Terminal
HOST_RECEIVE	Terminal is waiting for transaction response	Terminal
TRANSACTION_APPROVED	Show transaction completion screen with status approved.	ECR
TRANSACTION_DECLINED	Show transaction completion screen with status declined	ECR
TRANSACTION_ABORTED	Show transaction completion screen with status aborted	ECR

The TRANSACTION_* ReferenceID values can only be used in DisplayRequests that are used together with PINRequest. They are not relevant and cannot be used in any other scenario. For the full flow, see PIN entry controlled by the ECR. Ask your Aera contact for the appendix that describes the full PIN message flow.