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PosCommon Class (POS for .NET v1.12 SDK Documentation)

2/27/2008

PosCommon is the Base class for all specific Interface classes, and all Service Objects indirectly derive from it. PosCommon defines the common properties, methods, and events that the Unified Point of Service (UPOS) specification requires in all device classes.

PosCommon Properties

The following table describes the properties of the PosCommon class available to POS applications.

Property Type Description

CapCompareFirmwareVersion

bool

Indicates whether the Service Object and device supports comparing the firmware version in the physical device against that of a firmware file.

CapPowerReporting

PowerReporting enum

Indicates the power reporting capabilities of the device.

CapStatisticsReporting

bool

Indicates whether the device can accumulate and can provide various statistics regarding usage.

CapUpdateStatistics

bool

If set to true, some or all of the device statistics can be reset to 0 (zero) using the ResetStatistic method for one update and ResetStatistics method for a list of updates, or updated using the UpdateStatistic method for one update and the UpdateStatistics method for a list of updates with the corresponding specified values.

CapUpdateFirmware

bool

Indicates whether the device's firmware can be updated via the UpdateFirmware method.

CheckHealthText

string

Indicates the health of the device.

Claimed

bool

Indicates whether the device is claimed for exclusive access.

DeviceDescription

string

Holds a string identifying the device and the company that manufactured it.

DeviceEnabled

bool

Indicates whether the device is in an operational state.

DeviceName

string

UPOS calls it PhysicalDeviceName; OPOS calls it DeviceName.

DevicePath

string

Set by POS for .NET for Plug and Play devices. For non-Plug and Play devices, DevicePath can be assigned using a configuration file.

FreezeEvents

bool

When set to true, the application has requested that the Service Object not deliver events.

PowerNotify

PowerNotification enum

Holds the type of power notification selection made by the application.

PowerState

PowerState enum

Holds the current power condition.

ServiceObjectDescription

string

Identifies the Service Object supporting the device and the company that produced it. This property is listed as DeviceServiceDescription in the UPOS specification.

ServiceObjectVersion

System.Version

Holds the Service Object version number. This property is listed as DeviceServiceVersion in the UPOS specification.

State

ControlState enum

Holds the current state of the device.

SynchronizingObject

ISynchronizeInvoke

Gets or sets the marshalling object for event handler calls from a POS event.

PosCommon Methods

The following table describes the methods of the PosCommon class available to applications.

Method Return Type Description

CheckHealth

string

Performs a health check on the device. The type of check to be performed is indicated by the HealthCheckLevel parameter. The method also updates the CheckHealthText property.

Claim

void

Requests exclusive access to the device.

Service Object writers are advised to only throw exceptions in unexpected conditions; for example, OutOfMemory. Otherwise, Service Objects should return True if the device was claimed and False if a time-out occurred.

Close

void

Releases the device and its resources.

CompareFirmwareVersion

CompareFirmwareResult

Determines whether the version of the specified firmware is newer than, older than, or the same as the version of firmware in the physical device.

DirectIO

DirectIOData

Used to communicate directly with the Service Object.

In the UPOS specification, it has two in/out parameters. As used by POS for .NET, this method returns a structure and no in/out parameters.

Open

void

Opens a device for subsequent input/output processing.

Release

void

Releases exclusive access to the device.

ResetStatistic

void

Resets the specified statistic to zero.

Used in POS for .NET for operations on a single statistic.

ResetStatistics

void

Resets all statistics for a specified category to 0 (zero).

ResetStatistics

void

Resets the specified statistics to 0 (zero).

ResetStatistics

void

Resets all statistics associated with a device to 0 (zero).

RetrieveStatistic

string

Retrieves the specified device statistic.

Used in POS for .NET for operations on a single statistic.

RetrieveStatistics

string

Retrieves all device statistics.

RetrieveStatistics

void

Retrieves the statistics for the specified category.

RetrieveStatistics

void

Retrieves the specified statistics.

UpdateFirmware

void

Updates the firmware of a device with the version of the firmware contained in the specified filename.

UpdateStatistic

void

Updates a statistic.

Added to POS for .NET for operations on a single statistic.

UpdateStatistics

void

Updates a list of statistics with the corresponding specified values.

UpdateStatistics

void

Updates the specified category of statistics with the specified value.

PosCommon Events

The following table describes the PosCommon class events.

Method Description

DirectIOEvent

Raised by the Service Object to communicate information directly to the application.

StatusUpdateEvent

Raised by the Service Object to alert the application of a device status change.

Example

The following code example demonstrates how to use the properties and methods common to all Service Objects to display information about a connected device.

    // Create a dervied class of PosCommon
    public class PosCommonSample: PosCommon
    {
        // Implement all base methods and properties.
        // ...                
    }

    // Create instances for the example.
    PosExplorer explorer = new PosExplorer();
    PosCommonSample pcs = new PosCommonSample();
    DeviceInfo device = explorer.GetDevice("MSR");
    pcs = (PosCommonSample)explorer.CreateInstance(device);
                
    // Open and claim the device, then print information
    // about the device to the console.
    pcs.Open();
    pcs.Claim(1000);
    Console.WriteLine("Name: {0}", pcs.DeviceName);
    Console.WriteLine("Description: {0}", pcs.DeviceDescription);
    Console.WriteLine("Path: {0}", pcs.DevicePath);
    Console.WriteLine("Enabled: {0}", pcs.DeviceEnabled);

    pcs.Close();

See Also

Concepts

POS for .NET Class Tree