VPOS Media | MDB Basic Configurations

Set up MDB transaction scenarios for VPOS Media 4 and Media 4 Mini in Nayax Core. Compare Start with Card (Pre-Selection), Pre-Authorization, and Always Idle (Level 3) configurations with BASIC templates and side-by-side setting comparisons.

General

VPOS Media| MDB Basic Configuration

The Multi-Drop Bus (MDB) protocol defines how vending machines and payment systems communicate. Each MDB level determines when and how a transaction starts, affecting convenience, speed, and customer experience. Use this guide to configure your VPOS Media 4 and Media 4 Mini devices for one of three MDB scenarios in Nayax Core.

What are Basic Templates?
BASIC templates give you a pre-configured starting point for your VPOS Media device. Instead of building your configuration from scratch, enter the template tag into the Machine Model field under the General tab in Nayax Core.
This auto-populates the essential fields in the Default Configuration tab with the recommended structure for your chosen mode. From there, set the values for each parameter and add any additional attributes your machine requires.

 

Machine Model Template Tag:
MDB StartWithCard Basic

MDB Level 1 · Pre-Selection

Customer taps or inserts their card, then selects a product.

Card first, choose second.
How to Set Up "Start with Card" MDB Level 1 Pre-Selection | VPOS Media

Machine Model Template Tag:
MDB PreAuth Basic

MDB Level 1 · Pre-Authorization

Customer taps or inserts their card. A pre-authorized amount is charged before product selection. 

How to Set Up "Start with Card" MDB Level 1 Pre-Authorization | VPOS Media

Machine Model Template Tag:
MDB Always Idle Basic

MDB Level 3 · Always Idle

Device stays idle. Customer selects a product on the machine, then pays.

Browse first, pay second.

How to Set Up MDB Level 3 Always Idle | VPOS Media

How to Configure:

Nayax Core > Operations tab > Machines > locate your machine > General tab > Model Name field > Enter template tag

The template auto-populates the essential fields in Default Configuration. Operators must set values for each parameter.

 
*Differs between MDB templates
Operator Sets = Value required to be set by the operator
These attributes control the MDB behavior for each mode. Values shown are Nayax recommended defaults. 
 
Nayax Core Field

MDB Level 1 · Pre-Selection
Machine Model: Start with Card Basic

MDB Level 1 · Pre-Authorization
Machine Model: MDB
Pre-Authorization Basic

MDB Level 3 · Always Idle
Machine Model: MDB Always Idle Basic

Card Readers
Card Reader MDB Level 1 1 3
Decimal Place 2 2 2
EMV Contactless Transaction Limit 0 0 0
*Transaction Start Method Mag+Contact+Contactless Mag+Contact+Contactless Product
Communication
Communication Mode MQTT Enabled MQTT Enabled MQTT Enabled
Device Features
*Data Reduction
If DEX is connected, adjust the DEX settings
16 No DEX on Restart 16 No DEX on Restart 16 No DEX on Restart
MDB
Cashless MDB Address Enable Cashless Device #1
(Select the checkbox)
Enable Cashless Device #1
(Select the checkbox)
Enable Cashless Device #1 
(Select the checkbox)
*MDB Flags 02 Pre-selection Enabled *Flags Disabled 02 Pre-selection Enabled
*MDB Level 3 Optional Features Enable "Always Idle" state
Payment
Default Credit Not Required Operator Sets 
Enable (Select the checkbox)
Higher than most expensive product
Operator Sets 
Enable (Select the checkbox)
Higher than most expensive product
 
 
⚠ IMPORTANT NOTE  
  • BASIC = minimum required fields. These templates contain only the essential configuration.
  • Operators must add any additional attributes they require beyond this basic setup.
  • Default Credit must always be set it pre-authorizes payment to cover purchases and prevents non-payment.
  • After configuring each attribute, select its checkbox on the left. When ready, click ActionsUpdate Queue to push the changes to your device.
 

Best Practices

FAQ

FAQ

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