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VME Bus Mechanical Board Dimensions Drawing

This is a diagram of a VME bus or VXI bus 'D' size card. The maximum size of the D-style board is shown below. The connector locations and component keep-out areas are indicated, face-plate screw locations are also indicated. The normal width, or thickness, for a VME [or VXI board] is 90 mil. if the card requires an increased thickness because of an increased number of layers then the card may be milled top and bottom. Once the edges are milled the card will be able to slide in a standard 90 mil card guide. Additional data is provided below, Component height & other detailed data on VME may be found under VME bus, or VXIbus. The 9U boards, in the picture to the right, is identifiable by the three individual connectors on the backplane [J1, J2 & J3]. Note there is no sub-frame in the card cage to accept either a 3U or 6U size card.

9U Cards in a Chassis

VMEbus Mechanical Dimensions, D Size

Mechanical drawing; VME/VXI D Size Printed Wiring Board

IEEE 1101.1 Base Document for Mechanics ~ Defines 3U/6U/9U (high) x 100/160/220/280/340/400mm (Long) cards
IEEE 1101.10 Mechanics for VME Boards and Subracks
IEEE 1101.11 Mechanics for Rear Transition Modules

Three card heights are allowed with VME; 3U, 6U, or 9U; a single slot card is 6T wide. Length is either 160mm or 340mm (Norm)
Height is given in 'U' [1U = 43.60mm], Length is given in 'mm',
Width is given in 'T' or HP [1HP = 5.08mm [HP: Horizontal Pitch]; Card sizes listed below are one slot or 6T wide
A size PWB Dimensions = 3U x 160mm, ... H x L x W {@ width=6T}
B size PWB Dimensions = 6U x 160mm,
C size PWB Dimensions = 6U x 340mm,
D size PWB Dimensions = 9U x 340mm [This topic]
A, B, C, and D are VXI terms. VME normally only references 3U or 6U by a length

Note the front panel hole locations, and the one near the real panel to support the connectors.
The VME Board Height is also defined by a component keep-out area, called usable component area in the graphic.
Of course the Physical size are shown by the mechanical dimensions called out in the diagram.

Back to the main VMEBus page for a description of the VMEbus and VME component links.
Back to the main VXI Bus page for a description of the VXIbus and VXI component links.

Related VME Engineering Terms: VXI, VXI-Bus, VMEbus
Euro-Card size, Embedded Computer bus, VME Card Size, and VME Board Length

The fixed backplane connectors are referred to as J1, J2 & J3, the movable board side connectors are referred to as P1, P2 & P3.
A Jack [J1 for example] is the fixed portion of a two-connector system, while a plug [P1] is the movable portion of a two-connector system.
The backplane is considered the fixed portion of the two connectors, while the removable interface cards are considered the movable portion.

How tall is a VME card is was defined by IEEE 1014-1987, as is how long a VME card is, both combined being called the Form Factor.
The terms Circuit Card Assembly [CCA], and Printed Wiring Board [PWB] are used interchangeable.

Topic Navigation: Engineering Home > Interface Buses > Embedded Backplane Buses > VMEbus Description > 9U D-size Card Dimensions.

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