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This page will explore the essential components and configurations needed to establish and manage the connection between your application and Nayax’s payment devices using the Marshall SDK. This includes:
  • Handling events through the vmc_link_events_t interface.
  • Understanding the structure of vpos_config_t class.
Refer to the following sections for more information. The vmc_link_events_tInterface defines the events related to the communication link between the vending machine controller (VMC) and Nayax devices. Implementing this interface enables your application to respond to critical events that occur during the device’s operation. The following code block presents how to add the interface: 
public interface vmc_link_events_t
void onReady(vmc_link.vpos_config_t config);
void onCommError();

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Interface Methods

The table below describes the available methods of the interface.
MethodDescription
onReady()This method is called when the link with the VPOS (Vend Point of Sale) is successfully established and the device is ready for vending operations. It provides the VPOS’s configuration details.
onCommError()This method is invoked when a communication error occurs between the VMC and the VPOS, allowing your application to handle such errors appropriately.

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VPOS Configuration Class

The vpos_config_t class encapsulates the configuration settings for the VPOS, which are communicated between the VMC and the device. The following code block lists all available configurations: 
public static class vpos_config_t 
      public byte   prot_ver_major;
      public byte   prot_ver_minor;
      public byte   language;
      public byte[] country_code;
      public byte[] currency_code;
      public byte   decimal_place;
      public byte[] vpos_serial;
      public int    machine_type;
      public byte[] merchant_id;
      public byte[] acquirer_terminal_id;
      public byte[] machine_location;

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Class Parameters

The table below provides a detailed description of the parameters.
ParameterType (inferred)Description
prot_ver_majorintThe major version of the Marshall protocol.
prot_ver_minorintThe minor version of the Marshall protocol.
languageStringThe language setting of the VPOS.
country_codeStringThe country code in ISO format.
currency_codeStringThe currency code in ISO format.
decimal_placeintThe price is represented as 10 exponents. For example, if the decimal place is 2 and the requested price is 100, then the actual cost is 1.00 (with 2 decimal places).
vpos_serialStringThe serial number of the VPOS.
machine_typeStringThe type of machine connected to the VPOS.
merchant_idStringThe merchant ID.
acquirer_terminal_idStringThe acquirer terminal ID.
machine_locationStringThe location of the machine.

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Callback function

To register the callback events for link operations, use the following method: 
public vmc_link set_events(vmc_link_events_t events);
By understanding and implementing these configurations and methods, you can effectively manage the communication link and event handling for Nayax payment devices, ensuring reliable and efficient vending operations.