Introduction:
The Optoboard System is the data aggregation and signal conversion stage of the ATLAS ITk Pixel data transmission chain. The basic working principle is:
- DATA: 6x 1.28 Gbps electrical links from the front-end modules are serialized into 1x 10.24 Gbps optical link and transmitted to the backend (FELIX).
- CMD: 1x 2.56 Gbps optical link with trigger and command are deserialized into 8x 160 Mbps electrical links and transmitted to the front-end (ITkPix). Also the Optoboard gets controlled through the optical link.
One Optoboard consists of:
- 4 lpGBTv1: one as a master available through IC, three as slaves controlled through I2C controller of the master. Manual/description here.
- 4 GBCR2: all controlled through lpGBT master I2C controller. Manual here.
- 1 VTRx+: controlled through lpGBT master I2C controller. Description here.
- 1 bPOL2V5 carrier board: houses the bPOL2V5 ASIC that converts 2.5 V to 1.2V. Datasheets here.
Specific for SLAC's test-Optopanel will be marked in red .
Mechanics:
- Up to 8x Optoboards are housed in one Optobox. One Optobox consists also of:
- 1 Powerboard: hosts 5 bPOL12V ASICs (conversion 9 V to 2.5 V) and 1 MOPS chip
- 1 Connectorboard: handles power distribution form the 5 bPOL12V to the 8 Optoboards according the SP chain powering/detector layout.
- Up to 28x Optoboxes (14x normal, 14x mirrored) are housed in one Optopanel.
- Each side of the ITk has 4 Optopanels.
Currently specific for SLAC IS demonstrator:
4x Optoboard V2.1 are housed in one Optobox. This Optobox is housed in a Test-Optopanel.
Interfaces:
Please refer to our Interface Document here. All the connectors of the Optoboard System is explained there.
Schematics:
All schematics for all of Berns designed PCBs can be found here.
Optoboard sytem support:
We collect support requests and general questions on our Mattermost channel Bern-Optoboard (invite link).
Optoboard software for FELIX:
We created a repository with scripting software to easily configure the Optoboard: https://gitlab.cern.ch/bat/optoboard_felix. A lot is documented in the readme and wiki of the repository.
The repository is located in the directory:
/home/itkpix/optoboard-system
To configure an Optoboard V2.1 with the default configurations found simply run these scripts:
In a first terminal felixcore:
cd /home/itkpix/felix-sw/flx-sw-2022-08-11 # or another felix-sw version source setup.sh x86_64-centos7-gcc11-opt/felixcore/felixcore -d 0 --data-interface lo --elinks 0,4,8,12 # starts felixcore, check your links!
Note that the elinks might change according your connectivity scheme. More information from Ismet here.
In a second terminal do:
source flx_opto_setup.sh # if FELIX server restart or stuck: source flx_opto_setup_fresh.sh cd optoboard_felix python quick_start.py -v 1.3 -s 00000000 -G 0 -d 0
The -s
specifies the serial number used (00000000 is the default one for Optoboard V2.1), -G
is the link number of FELIX and -d
the FELIX device. If -s
is set to 00000000 and -v 1.3
, optoboard_felix sends the parameters in the config ~/optoboard_felix/configs/optoboard_lpgbtv1_gbcr2_vtrxv1_3_default.json
to the lpGBTs, GBCR and VTRx+. Check the FELIX documentation or the optoboard_felix readme for more information on this.
After the fibre fanout is installed, configuring the Optoboards will look similar to this:
python quick_start.py -v 1.3 -s 00000000 -G 0 -d 0 python quick_start.py -v 1.3 -s 00000000 -G 1 -d 0 python quick_start.py -v 1.3 -s 00000000 -G 2 -d 0 python quick_start.py -v 1.3 -s 00000000 -G 3 -d 0
Or ideally if separate configs are created in ~/optoboard_felix/configs
:
python quick_start.py -v 1.3 -c 2400006 python quick_start.py -v 1.3 -c 2400003 python quick_start.py -v 1.3 -c 2400007 python quick_start.py -v 1.3 -c 2400011
Note that in this case the connected FELIX fibre channel has to be set inside the configuration file as described in the readme here.
In a currently ongoing effort by Bern PhD student Daniele dal Santo, the software will be integrated into the ITk demonstrator software itk-demo-sw.
Test-Optopanel at SLAC:
The test-Optopanel houses one Optobox with 4 Optoboards. It has a twinax inlet (round) and a fibre outlet (rectangle). The Optobox is mounted on a cooling plate with two 8 mm pipes. The
A collection of photographs from the test-Optopanel and its sister at CERN SR1 can be found here. See also this Twiki here of the SR1 test-Optopanel which has similiar information (but some very different configurations).
Optoboards:
slot: | OB1 | OB2 | OB3 | OB4 | OB5 | OB6 | OB7 | OB8 |
---|---|---|---|---|---|---|---|---|
serial: | 2400006 | - | 2400003 | - | 2400007 | - | 2400011 | - |
powering from bPOL: | A | A | B | B | C | C | D | D |
FELIX link: |
Connectors:
Check the above interfaces document for more detailled description.
Banana plugs are labelled according to powered bPOL12V.
Cooling and dry air inlet/outlet: FESTO 8 mm
DCS:
Currently no MOPS is mounted on the Powerboard inside the test-Optopanel (due to availability). We will ship one as soon as we got our hands on them.