This chapter describes the basic VME option functionality. It contains the following sections:
“VME Option Product Description” describes basic product functionality.
“Restrictions and Important Notes” describes special VME restrictions.
“Safety Considerations” describes product safety instructions.
The VME option is designed to provide VME bus access to Origin200 GIGAchannel server, Origin2000, and Onyx2 deskside and rackmount systems. This option kit consists of a VME interface board, VME XIO board, Xtown VME cable, and VME grounding cable (see Figure 1-1). One of the three user-supplied VME chassis described below is also required for proper system operation.
The VME XIO board installs into any Origin or Onyx2 XIO system slot. The VME interface board plugs into slot 1 in the VME chassis and functions as the system controller. The Xtown VME cable and VME grounding cable connect directly to the both boards. According to specific customer needs, VME boards are inserted into the VME chassis to provide VME device integration within an Origin or Onyx2 system.
The VME interface board is available in two sizes: 6U and 9U. The VME chassis is available in three sizes: 6U/21-slot, 6U/5-slot, and 9U/5-slot. Silicon Graphics does not supply the VME chassis, but has qualified three chassis configurations that are available from ELMA Electronics. These VME chassis are specially designed to meet Silicon Graphics VME grounding and EMI requirements. Customers can purchase a VME chassis from ELMA Electronics. (For detailed ordering information, call 1-510-656-5829 in the U.S.A. or access their web page at http://www.elma.com .)
Installation and initial verification of the VME option must be performed by authorized Silicon Graphics personnel. For more information, contact your nearest Silicon Graphics representative.
Silicon Graphics ensures proper VME board operation only when used in an authorized VME chassis obtained from ELMA Electronics.
If you are running IRIX 6.4 on the host system, you must install patches to the operating system.
To ensure proper operation, both the Silicon Graphics system and the VME chassis must be powered by the same AC power supply so that they share a common ground.
Ground cables cannot be extended.
Each Origin or Onyx2 system supports a maximum of 5 VME option boards. Each VME XIO board requires one XIO slot.
When connecting multiple VME chassis to the same Silicon Graphics host system, separate ground cables must be attached between each VME XIO board and each VME interface board.
Due to conflicting cooling requirements, the VME chassis cannot be installed in a Silicon Graphics rack.
The number of available slots in each VME chassis is one less than the total slot number, because slot 1 is required for the VME interface board.
The Silicon Graphics VME interface board must be placed in the VME chassis slot 1, and provides system controller functions. No other card in the VME chassis can be used as the system controller.
Jumper settings are required only for Origin200 GIGAchannel server operation.
Daisy-chain operation within the chassis is configured automatically, so that no backplane jumpers are required if slots are skipped.
 | Note: Each ELMA VME chassis has been certified and licensed by international safety agencies for use either as a stand-alone unit or for installation in a third-party 19-inch equipment rack. Regardless of whether the VME chassis is set up and installed by the customer or by a Silicon Graphics authorized service person, installation in a rack may require submittal to an approved safety agency for their evaluation and certification or licensing of the new rack-system combination. |
 | Caution: The Silicon Graphics VME interface board is designed in compliance with standard ELMA/VME mechanical specifications. It is also designed to meet FCC Class A regulations when installed in a Silicon Graphics approved chassis in which all slots are filled either with shielded blank panels or with VME boards that include shielded front panels. |
If your VME boards are not compliant with ELMA/VME mechanical specifications, VME board problems can occur. The VME interface board has a row of grounding fingers adhered to the side of the front panel that provide EMI shielding (see Figure 1-2). In some cases, adjacent IC leads from non-compliant ELMA/VME boards can contact these grounding fingers and cause the VME board to short out.
Therefore, it is recommended that you observe the following precautions when installing non-compliant ELMA/VME boards. With the system turned off, install a VME board in VME chassis slot 2 and visually inspect it to ensure that it is not contacting the VME interface board grounding fingers. If the adjacent VME board is contacting the grounding fingers, one of the following options will resolve the problem. (Note that these options apply only to systems where EMI shielding is not required.)
Remove the VME board from the VME chassis slot 2 and always leave slot 2 empty.
Cover the VME interface board grounding fingers with a non-conductive, protective tape.
Remove the grounding fingers from the VME interface board.
It is recommended that the Silicon Graphics VME interface board be used only with other ELMA/VME-compliant boards. The customer assumes full responsibility for all non-compliant ELMA/VME boards installed in the system. Silicon Graphics is not liable for any system problems that occur as a result of using non-compliant ELMA/VME boards.
 | Warning: All board installations or removals should be performed only by Silicon Graphics trained or certified personnel. Unauthorized access to the cardcage area could result in system damage or even bodily harm, and could void the warranty or safety agency approvals for the system. |
