DI/OT 3U crate project

Project description

The 3U crate is a main component of the Distributed I/O Tier hardware kit. The enclosure is assembled using 3U sub-rack components compatible with the IEC 60297-3 and IEEE 1101.10-1996 mechanical standards. These are low-cost aluminum elements available in the products portfolio of all major crate vendors. The crate provides:

• in-house designed 9 slot backplane compatible with CompactPCI Serial standard
• support to host Rear Transition Modules (RTMs) - the RTMs are usually fully passive boards that provide an interface with external equipment through a direct RTM connector to the corresponding Peripheral Board
• two power supply slots (two power backplanes) to host dual modular redundancy power supplies in load-sharing configuration
• optional 1U fan tray that can be mounted either below or above the main 3U crate

DI/OT crate 19" rack variant:

DI/OT crate tunnel variant:

DI/OT main backplane

The DI/OT main backplane is a KiCad design compatible with the CompactPCI Serial standard. It provides 9 slots (1 System Slot and 8 Peripheral Slots) and the support for RTMs.

DI/OT main backplane(front view):

DI/OT main backplane topology:

The backplane provides:

• a star topology of 144 LVDS lanes in total (18 LVDS lanes per Peripheral Slot) used as differential or single-ended I/Os to implement communication between the System and Peripheral Boards. Out of those, 1 LVDS lane per Peripheral Slot is reserved for the distribution of low-jitter clock and 2 LVDS lanes are designated for high-speed communication
• the Reset line driven by the System Slot to reset all the Peripheral Boards
• a set of 5 multidrop lines (multidrop IRQs) can be used as interrupt lines of 5 priorities, or for any other one-to-many signaling.
• a star of single-ended presence detection signals and a service I2C bus (shared among all the slots)
• distribution of two auxiliary voltages to all Peripheral Slots.

Release

Status

Contacts

• Greg Daniluk - CERN