VXI SupportVXI/VME Multi-Mainframe/Multi-Chassis Configuration: Logical Address WizardThe Logical Address Wizard is a useful tool for determining the logical address assignments that you can use for the devices in a multi chassis VXI/VME system. Download Logical Address Wizard DISCLAIMER: The Logical Address Wizard is provided AS IS and National Instruments can not provide support for it or endorse its suitability for use for any particular application. National Instruments may also NOT be held liable for any loss or damage to any equipment (computing, instrumentation etc.) that may result from the use of this software. The Wizard uses the rules documented in the System Configuration sections of the VXI-MXI-2 and VME-MXI-2 user manuals to determine the set of logical addresses that you can assign to the devices in each chassis. One must carefully select the logical address assignments for devices in a multi mainframe VXI/VME configuration. The logical address wizard is helpful in making these choices. Consider a system with the following setup (this is the same setup used in the example in the System Configuration section of the VME-MXI-2 User Manual):
For the purposes of this discussion, we will consider MXI bus devices A and B to be VXI or VME chassis with a slot 0 MXI-2 extender. The system in the example uses an embedded slot 1 controller (such as a VMEpc-650 series controller) and so we select a VXIpc for the Resource Manager in the Logical Address Wizard dialog.
Next, we add 2 extender devices to frame 0 and also configure the properties of frame 0 to set the number of logical addresses required for devices OTHER than the slot 0 device and extenders. In this example, this is 0 as the top-level mainframe only contains a slot 0 device and two MXI-2 extenders.
At this point, we add four mainframes under the first extender (Extender 0) and 1 frame under the Extender 1.
We then add another extender and frame under Frame 4 and configure the number of logical addresses used by each frame (excluding slot 0 and extender devices).
Once we have completed entering the system information, the LA Wizard lists a recommended range of addresses for each of the devices in the chassis.
In this example, VME bus Mainframe #1 (Frame 0 in the LA Wizard screen shots) contains a MXI-2 that is configured for logical address 1 (Extender 0) and also contains another MXI-2 extender that is configured at LA 2 (extender 1). Extender 1 is connected to VME bus Mainframe #6 (Frame 5 in the LA Wizard screen shots) that contains a MXI-2 extender at LA 62. Extender bus 0 is used to connect to MXI bus device A, which has a MXI-2 extender at logical address 84 and two instruments at logical addresses 85 and 86. VME bus Mainframe # 3 (Frame 4 in the screen shots) contains two MXI-2 devices. The slot 0 device is configured at LA 88 and the non-slot 0 device is configured at LA 89 (Extender 3 in the screen shots). Extender 3 is then attached to VME bus mainframes #4 and #5 (Frames 7 and 8 respectively in the screen shots). The following table lists the range of logical addresses that can be used for VXI instruments in each chassis.
Note: The concept of a logical address does not apply to VME devices. The italicized logical addresses listed in the table are the addresses that one could use if a VME mainframe were replaced with a VXI mainframe and VXI devices. Observe that the Logical Address Wizard tool generates a set of logical address assignments that may not leave room for future expansion. Hence, you may want to reserve some logical addresses in each mainframe simply by increasing the number of instruments specified in the property dialog for each frame. It should be noted that the list of logical addresses generated by the LA Wizard are not the only set of logical addresses that will support the desired configuration layout. The range of logical addresses generated by the LA wizard simply represent the smallest range of logical addresses that will support the desired configuration. As a general rule of thumb, the logical address of the slot 0 MXI-2 device should be a multiple of 2. |
