> For the complete documentation index, see [llms.txt](https://developer.magtek.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/notifications/0x18nn-from-user-interface/0x1803-user-interface-host-action-request.md). # 0x1803 - User Interface Host Action Request This notification requests that the host take action during operations involving the device’s User Interface modules. For this notification, Notification Detail described in [**Notification Message**](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/message-format-and-structure/message-structure#notification-message-format) contains one byte each: * The User Interface Module (UI) involved * The Reason (Rsn) for the notification (UI Event) * Detail (Det) about the notification that has different meanings depending on the Reason, and * An Extra field (Ext) that has different meanings depending on the Reason. ## Notification Detail Codes - 0x1803 {% hint style="info" %} Module 0x00 Miscellaneous contains UI notification detail codes that are not specific to a particular UI module. {% endhint %}


UI	Rsn	Det	Ext	Meaning

{% hint style="info" %} Module 0x01 Touchscreen contains UI notification detail codes that are specific to the touchscreen module (Touch Only). * Reason 0x01 = Signature Capture * Reason 0x02 = Functional button selected * Reason 0x03 = Button text string selected * Reason 0x04 = Button $Amount selected * Reason 0x05 = Present card functional button Right is selected {% endhint %}


UI	Rsn	Det	Ext	Meaning
01	02	01	00	Touchscreen, Functional button Left selected
01	02	02	00	Touchscreen, Functional button Middle selected
01	02	03	00	Touchscreen, Functional button Right selected
01	03	01	00	Touchscreen, Text string button 1 selected
01	03	02	00	Touchscreen, Text string button 2 selected
01	03	03	00	Touchscreen, Text string button 3 selected
01	03	04	00	Touchscreen, Text string button 4 selected
01	03	05	00	Touchscreen, Text string button 5 selected
01	03	06	00	Touchscreen, Text string button 6 selected
01	04	00	00	Touchscreen, $Amount button selected, Data Attached contain the amount selected as described in Table - Notification Payload for $ Amount button selected, Data Attached
01	05	00	00	Touchscreen, Present card functional button Right selected

{% hint style="info" %} Module 0x02 Display contains UI notification detail codes that are specific to the display module. The device primarily uses these notifications to request that the host stand in as a display to interact with cardholders / operators when the device does not have a display of its own or the display is configured with [**Property 1.2.3.1.2.3**](https://developer.magtek.com/api-and-command-reference/dynafamily-programmers-manual/properties/1.2.nnnn-device-settings/1.2.3.nnn-user-interface-settings-a#property-1.2.3.1.2.3-send-ui-notifications-along-with-showing-message-on-the-display-display-only) Send UI notifications along with showing message on the display. * Reason 0x01 = Display Message Request * Reason 0x02 = Cardholder Selection Request * Reason 0x03 = Online PIN Request (MAGTEK INTERNAL ONLY FOR NOW {% endhint %}

Rsn

Det

Ext

Meaning

Display, Display Message, No Data Attached, Clear Display.

The host should clear any existing messages it is currently displaying.

Display, Display Message, Data Attached, No Cancel Function

In this case, the notification includes additional data and display control, defined in Notification Payload for Display Message Request Notifications, in the Notification Payload portion of the Notification Message.

This notification is for simple messages. The host should show the requested message until another notification arrives or until the host needs to use the display for its own purposes. For example, during a transaction, this notification will pass along the simple messages in the transaction sequence like CARD READ OK - REMOVE CARD , THANK YOU , and WELCOME .

Display, Display Message, Data Attached, Include Cancel Function

The host should show the requested message and should allow the request to be canceled by a cardholder or operator. For example, during a transaction, this notification will pass along the simple messages in the transaction sequence like “TAP, INSERT, or SWIPE CARD,” where cancelation is appropriate. If the cancel button involves canceling the whole transaction, the host should send Command 0x1008 - Cancel Transaction.

Display, Cardholder Selection, Data Attached, Reserved

In this case, the notification includes additional data and display control, defined in

Notification Payload for Cardholder Selection Notifications (No Display Only), in the Notification Payload portion of the Notification Message.

The host should show the requested selection, then send Command 0x1802 - Report Cardholder Selection to device to return the cardholder’s selection to the device.

## Notification Payload for Display Message Request Notifications


Tag	Len	Value / Description	Typ	Req	Default
Beginning of Notification Message
1803 = Notification 0x1803 - User Interface Host Action Request
/81	01	Reserved for time functions. 0x00	B	R
/82	01	Append or Clear Display · 0x00 = Append the message(s) on the next available row. · 0x01 = Clear the display first and display the requested message on the first row.	B	R
/83	var	Message This parameter is a set of one or more ASCII strings the host should show, with each string terminated by any one of the following characters. MagTek recommends proceeding to the next row on receiving any of these characters: · Null (0x00) · LF (0x0A) · The end of the Message parameter.	B	R
/85	var	Enhanced Application Select Message For Contactless, this parameter will return the PPSE response starting from tag BF0C BF0C <LEN><VALUE> For Contact, this parameter will return all available AID returned from the PSE or List Of AIDs, from tag 70 70 <len> 61 <len> 4F<len><value of AID> 50<len><value of Application Label> 87<len><value of Application Priority Indicator> 61 <len> 4F<len><value of AID> 50<len><value of Application Label> 87<len><value of Application Priority Indicator, optional> If the GPO Response returns a Notification 0x0101 - Transaction Information Update of’69 85’, the response will be sent first by the device and this Enhanced Application Select Message will be sent again.	B	O
End of Notification Message

## Notification Payload for $ Amount button selected, Data Attached


Tag	Len	Value / Description	Typ	Req	Default
Beginning of Notification Message .
1803 = Command 0x1803 - Display Message (Display Only)
84	9	Amount selected payload	B	R
/9F02	6	Dollar and cents amount selected in BCD format	B	R
End of Notification Message

## Notification Payload for Cardholder Selection Notifications (No Display Only)


Tag	Len	Value / Description	Typ	Req	Default
Beginning of Notification Message
1803 = Notification 0x1803 - User Interface Host Action Request
/81	01	Time in seconds the device will wait for host to respond with Command 0x1802 - Report Cardholder Selection.	B	R
/82	01	Append or Clear Display · 0x00 = Append, display the messages on the next line. · 0x01 = Clear, clear the display first and display the requested message on the first line.	B	R
/83	var	Message This parameter is a set of one or more ASCII strings the host should show, with each string terminated by any one of the following characters. MagTek recommends proceeding to the next row on receiving any of these characters: · Null (0x00) · LF (0x0A) · The end of the Message parameter.	B	R
End of Notification Message

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