visa

Resource Names

Each device is identified by a resource name that specifies the type of connection used, location information and the device type.

USB Devices

USB[bus]::manufacturer::product::serial[::type]

The manufacturer and product identifiers must be given as hexadecimal numbers prefixed with 0x. The serial number is mandatory, even if the device would be unique otherwise.

Ethernet/VXI-11 Devices

TCPIP[interface]::host[::type]

Resource Manager

Access to resources is mediated through a resource manager; while technically there could be multiple instances, usually only the default resource manager is used.

A handle to the default resource manager can be obtained from the viOpenDefaultRM(3visa) function.

Finding Devices

If the resource name is not known in advance, the resource manager can be queried for a list of known devices by using the viFindRsrc(3visa) function.

This function returns a ViFindList object (along with the first known resource), and further resource names are then queried from the find list using viFindNext(3visa) before finally freeing the list using viClose(3visa).