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
Date | Release |
---|---|
17.08.2021 | v1.2 |
04.05.2020 | v1.1 |
Contacts
- Greg Daniluk - CERN
Status
Date | Event |
---|---|
May 2019 | CPCIserial backplane and Power backplane PCB design kick-off; backplanes development notes |
Nov 2019 | Mechanical crate design kick-off; crate development notes |
Jan 2020 | Discussion with nVent/Schroff; Schroff meeting notes |
Marc 2020 | Crate mechanics release v1.0 |
Apr 2020 | Crate mechanics review of v1.0 with 15 engineers |
May 2020 | Crate mechanics release v1.1 |
3 Dec 2020 | First 2 prototypes delivered by nVent |
15 Jan 2021 | Crate prototype delivered by Creotech |
17 Aug 2021 | Ordering 25 v1.2 crates for lab and IT String tests at CERN |
10 Sep 2021 | Design of optional DI/OT fan tray finalised |
11 Oct 2021 | Ordered ten DI/OT fan tray prototypes |