Noun
subrack (plural subracks)
A narrow rack for computer equipment, designed to fit into a larger rack.
At the "back" of each card is one or more connectors, which plug into mating connectors on a backplane that closes the rear of the subrack. Source: Internet
Overview and history Equipment designed to be placed in a rack is typically described as rack-mount, rack-mount instrument, a rack mounted system, a rack mount chassis, subrack, rack mountable, or occasionally simply shelf. Source: Internet
As two 3U cards are shorter than a 6U card (by 33.35 mm), it is possible to install two 3U cards in one slot of a 6U subrack, with a mid-height structure for proper support. Source: Internet
The subrack consists of a series of slotted card guides on the top and bottom, into which the cards are slid so they stand on end, like books on a shelf. Source: Internet
This dimension refers to the subrack in which the card is to be mounted, rather than the card itself. Source: Internet
Two common heights are 3U (a 100 mm card in a convert subrack) and 6U (a 233.35 mm card in a convert high subrack). Source: Internet