Magtek MAGTEK User Manual download pdf (Page 60)

MagTek Communications Protocol, Driver Reference Manual

dwPropertyType

Property Type. When obtaining (McpGet) or modifying (McpSet) property values from the driver

or device, this field specifies the data type of the property value identified by either

dwPropertyID or lpszPropertyName. The lower four bits of the type specify the property type;

the upper four bits are reserved for future extensions (e.g. to specify that the property is

identified by name and not by numeric ID). The following types are defined: (upper 4 bits are

used specially)

Code Meaning

MCP_TYPE_NONE No type.

MCP_TYPE_DWORD 32-bit unsigned integer

MCP_TYPE_STRING Null terminated string of 8-bit ANSI characters.

MCP_TYPE_BOOLEAN Boolean value (True or False)

MCP_TYPE_BINARY Binary data

lpInBuffer

Pointer To Input (Request) Buffer. If a command contains data in addition to the Application and

Command IDs, the host application places it in this buffer. The length of the data in this buffer is

indicated by dwInBufferLen. Set to null if there is no additional data associated with this

command. Refer to the device's Command Reference Manual for the definition of the content of

this buffer. If this parameter is not null but dwInBufferLen is zero, the data will not be

transmitted.

dwInBufferLen

Length of data (in bytes) contained in the input buffer pointed to by lpInBuffer. Set value to zero

if there is no additional data associated with the command. This value will always be interpreted

as zero if lpInBuffer is null.

lpOutBuffer

Pointer To Output (Response) Buffer. If there is data being returned in the response to a

command, the MCP driver places the data in the output buffer pointed to by this member value.

The size of the buffer pointed to by this value must be specified in the dwOutBufferSize member

so that the MCP driver does not overrun the callers buffer. The length of the response is

indicated by the value in dwResponseLen. Refer to the device's Command Reference Manual for

the definition of the content of the buffer.

An error will be reported if this value is null and the device responds with data or if the amount

of data returned by the device exceeded the length of this buffer (dwOutBufferSize).

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Magtek MAGTEK User Manual Page 60