National Instruments NI-VXI

Chapter 2 Introduction to the NI-VXI Functions

5 NI-VXI User Manual

Because value is an output parameter, &value is used when calling

the function instead of value. The input parameters are la and reg.

Return Values and System Errors

All NI-VXI functions return a status indicating success or failure. The

return code of 0x8000 is reserved as a return status value for any

function to signify that a system error occurred during the function call

except for the commander word serial operations. This error is specific

to the operating system on which the NI-VXI interface is running.

Multiple Mainframe Support

The NI-VXI functions described in this manual support multiple

mainframes both in external CPU configurations and embedded CPU

configurations. The Startup Resource Manager supports one or more

mainframe extenders and configures a single- or multiple-mainframe

VXI/VME system. Refer to the VXIbus Mainframe Extender

Specification, Revision 1.3 or later, for more details on multiple

mainframe systems.

If you have a multiple-mainframe VXI/VME system, please continue

with the following sections. If you have a single-mainframe system,

you can skip to the Using NI-VXI section later in this chapter.

Controllers

A controller is a device that is capable of controlling other devices. A

desktop computer with a MXI interface board, an embedded computer

in a VXI/VME chassis, a VXI-MXI, and a VME-MXI may all be

controllers depending on the configuration of the system.

There are several types of controllers that may exist in a VXI/VME

system; embedded, external, and remote.

• Embedded controller—A computer plugged directly into the

VXI/VME backplane. An example is the National Instruments

VXIpc-850. All of the required VXI/VME interface capabilities are

built directly onto the computer itself. An embedded computer has

direct access to the VXI/VMEbus backplane in which it is installed.

• Remote controller—A device in the VXI/VME system that has the

capability to control the VXI/VMEbus, but has no intelligent CPU

installed. An example is the VXI-MXI-2. In NI-VXI, the

parent-side VXI-MXI-2 (that is, the VXI-MXI-2 with a MXI-2