VISA Map Address Function

Owning Palette: Low Level Register Access Functions

Requires: Base Development System

Maps a memory space specified by map base and map size.

The memory space that the function maps depends on the type of interface specified by VISA resource name and address space. After the window is mapped, VISA keeps track of the window that is mapped. This dictates that VISA can map only one window for each VISA session.

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address space specifies the address space to map. The following table lists the valid entries for specifying address space.
Value Description
VXI, VME, and GPIB-VXI VXI/VME A16 (1)

VXI/VME A24 (2)

VXI/VME A32 (3)

VXI/VME A64 (4)
PXI PXI Memory Allocations (9)

PXI Configuration (10)

PXI BAR0 (11) to PXI BAR5 (16)
VISA resource name specifies the resource to be opened. The VISA resource name control also specifies the session and class.
map base contains the offset (in bytes) of the memory to be mapped. The type of resource determines how map base specifies the offset.
  • INSTR Specific—Notice that map base specified in the VISA Map Address operation for an INSTR Resource is the offset address relative to the device's allocated address base for the corresponding address space that was specified. For example, if address space specifies VXI/VME A16, map base specifies the offset from the logical address base address of the specified VXI device. If address space specifies VXI/VME A24, VXI/VME A32, or VXI/VME A64, map base specifies the offset from the base address of the VXI device's memory space allocated by the VXI Resource Manager within VXI/VME A24, A32, or A64 space.
  • MEMACC Specific—For a MEMACC Resource, map base specifies an absolute address.
map size contains the amount of memory to map.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
access is reserved for future use and should be set to FALSE. This input is available only if you do not place a checkmark in the Restrict Access checkbox on the Configuration page of the Properties dialog box for the variable refnum.
VISA resource name out is a copy of the VISA resource name that VISA functions return.
error out contains error information. This output provides standard error out functionality.