Agilent Technologies
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VXI Common Problems

Bad Card
Unfortunately, a failed VXI card can have many different types of symptoms, and this is card dependent. Some failures can make the entire mainframe look bad. You must troubleshoot the system failure symptoms until you suspect a bad VXI instrument. If the card is having really serious problems, it could show up as bad in the ivxisc listing.

When Several Cards Look Bad
 If several cards appear to be bad, this is could be caused by one bad card, but it is usually an addressing problem. Either:

  • Two cards have been set to the same address. (Did someone change a card recently?)
  • Two VXI controllers have been set to the same address. (Did someone change a controller card recently?) This document explains how to use ivxisc to see if two mainframe controllers are set to the same address.
  • Two VXI controller cards could be swapped between mainframes.
  • Someone changed a card in slot 12 and forgot to move the VXI bus terminator resistor modules from the old card to the new card.

Controller Card Set to the Wrong Address
This often happens when someone replaces a bad controller card, and forgets to set the address. When this occurs, usually two VXI controllers end up at the same address. Specifically, this happens if you change the controller card in mainframe 2 or 3. (obviously, forgetting to set the address would not cause any problems if you replace the controller for mainframe 1, since the default address would work)

Thus, this always means that the controller card in mainframe 2 or 3 now has the same address as the controller for mainframe 1. The results: many cards do not work.

You can tell that two cards have the wrong address, because ivxisc ignores the "duplicate" controller card. For example: In a normal system, ivxisc will display information for three mainframes using this format:

VXI Bus: 1

Device Logical Addresses:

     1   65   80   85   95   100

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty         O  O  O           O  O  O        O
Single     X           X  X  X           X  X
 Device

Multiple Devices
VME
Failed

VXI Bus: 128

Device Logical Addresses:

      128   130   150   160   161   171   172   189   190   191

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty            O                       O     O
Single     X  X     X  X  X  X  X  X  X     X
 Device

Multiple Devices
VME
Failed

VXI Bus: 192

Device Logical Addresses:

      192   194   195   200   201   202   203   209   211   215   220

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty                                 O  O     O
Single     X  X  X  X  X  X  X  X  X        X
 Device

Multiple Devices
VME
Failed

This is an example of a normal system.

Now, look at this example from a system where VXI controller in mainframe 3 has accidentally been set to the same address as mainframe 1.
 

VXI Bus: 1
Device Logical Addresses:



      1   65   80   85   95   100
Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty         O  O  O           O  O  O        O
Single     X           X  X  X           X  X
 Device

Multiple Devices
VME
Failed
VXI Bus: 128
Device Logical Addresses:


      128   130   150   160   161   171   172   189   190   191
Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty            O                       O     O
Single     X  X     X  X  X  X  X  X  X     X
 Device

Multiple Devices
VME
Failed

Do you notice something missing?  The entire listing for mainframe #3 is gone.

Now assume the VXI controller in mainframe 2 has accidentally been set to the same address as mainframe 1.

VXI Bus: 1

Device Logical Addresses:

      1   65   80   85   95   100

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty         O  O  O           O  O  O        O
Single     X           X  X  X           X  X
 Device

Multiple Devices
VME
Failed

VXI Bus: 192

Device Logical Addresses:

      192   194   195   200   201   202   203   209   211   215   220

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty                              O  O     O
Single     X  X  X  X  X  X  X  X        X     X
 Device

Multiple Devices
VME
Failed


Now what is missing? The listing for mainframe 2!

Swapped Controller Cards

The ivxisc file will give very good clues that two controller cards are swapped, you simply need to know what to look for. Below is an example printout where the first (address 1) and third (address 192) mainframe controllers had been accidentally swapped.

VXI Current Configuration:

MXI Bus: 0

Device Logical Addresses: 0 1 128 192

Notice the addresses shown in italics below. Those card addresses don’t look right, they should be in the 1 to 127 number range. Actually there is nothing wrong with the card address settings. The address 1 controller card has been incorrectly placed in VXI mainframe 3. The address 1 controller still shows up at the top of the mainframe list, but it is controlling all of the mainframe 3 cards, as you can see in the Device Logical Address row. The cards in that mainframe are set to numbers in the 192 to 215 range. Note that address 1 in the Device Logical Addresses row is the address of the controller.

VXI Bus: 1

Device Logical Addresses:

      1   208   209   210   211   212

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty            O              O  O  O  O  O  O
Single     X  X     X  X  X  X 
 Device

Multiple Devices
VME
Failed

VXI Bus: 128

Device Logical Addresses:

      128   130   136   137   138   160   171   172   189   190   191

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty                                    O     O
Single     X  X  X  X  X  X  X  X  X  X     X
 Device

Multiple Devices
VME
Failed

Now look at the addresses below in italics. Those card addresses don’t look right either. These should be in the 192 to 215 number range. The address 192 (third) controller card has been incorrectly placed in VXI mainframe 1. The address 3 controller still shows up at the bottom of the mainframe list, but it is controlling all of the mainframe 1 cards, as you can see in the Device Logical Address row. The cards in that mainframe are set to numbers in the 1 to 127 range. The 192 at the end of the row is the address of the controller card. Normally that would show up as the first address in the row. However, remember that this row is always in numerical order, so the controller card address was pushed to the end.

VXI Bus: 192

Device Logical Addresses:

      65   90   93   104   110   115   116   117   118   192

Slots:     0  1  2  3  4  5  6  7  8  9 10 11 12
          -- -- -- -- -- -- -- -- -- -- -- -- --
Empty         O  O  O  
Single     X           X  X  X  X  X  X  X  X  X
 Device

Multiple Devices
VME
Failed