Essential Factors of the AdvancedTCA Standard

The mounting hardware specifications of the Advanced - TCA standard (PICMG 3.0) revolve around several key points — protection of electronic circuitry during hot-swapping, reliable engagement of the faceplate/circuit board during operation, and allowances for electrostatic discharge (ESD) or electromagnetic compatibility (EMC). A variety of hardware solutions developed according to these specifications offer advantages for telecom carriers, equipment OEMs, and contract manufacturers who adopt the standard and match the appropriate hardware solutions to their specific equipment designs.

Figure B. A complete AdvancedTCA front-panel fastening hardware solution includes a variety of handles, captive screws, grounding/ alignment pins and keying blocks.

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•Handles. AdvancedTCA handles serve multiple functions. Most important, they rotate to lock the board in place (ensuring that their board-edge connectors interface properly with the backplane of the shelf). They also provide a feature to activate and deactivate a microswitch to signal a hot-swap event. Designed to allow for maximum faceplate I/O space, they also provide an easy means of gripping the board for removal.

•Captive retention screws. These screws provide a physical means of anchoring board faceplates to the rack system. Their captive design assures that they stay with the board/faceplate assembly when it is removed, preventing loss of the fasteners and potential damage that could be caused by screws falling into other electronically active components.

•Alignment safety ground pins. These provide a physical alignment device for precise positioning, as well as a safe path for grounding the circuit board during insertion and removal.

•Keying blocks and Rear Transition Module (RTM) alignment pins. These components are designed to ensure proper positioning and contact between compatible circuit boards and their backplane connections. Different pin configurations are available to ensure that only appropriately designated boards can make an electronic connection.