Couple weeks of work documented in one elog...

V1725 serial numbers: 455, 392, 460, 462, 474

firmware: DPP-ZLE+

The 3818 kernel module not getting loaded on start-up... it is in /etc/rc.local, but not getting called

[root@ds-proto-daq ~]# grep 3818 /etc/rc.local 
# Load A3818 driver...
/sbin/insmod  /home/dsproto/packages/A3818Drv-1.6.0/src/a3818.ko

Called manually for now...

Reworked and cleaned up DEAP version of V1725 code
- Updated register map
- Removed smartQT code

Quick test: the V1725 seems to be getting busy at a maximum rate of 10kHz (with no samples being saved though).

Got preliminary documentation from CAEN for ZLE-plus firmware... posted here:

/home/dsproto/packages/CAEN_ZLE_Info

In particular, manual shows how the data structure is different for ZLE-plus data banks (as compared to V1720 ZLE data banks).

Fixed the /etc/rc.local setup so that the A3818 driver is loaded and mhttpd/mlogger is started on reboot.

Looking at V1725-ZLE register list.  I don't entirely understand how we are going to do the trigger outputs and the busy.  The manual makes it clear that the triggers from each pair of channels are combined together and send to the trigger logic.  So there should be 8 trigger primitives from the board.  The LVDS IO connector allows to configure groups of 4 outputs as being for either the trigger outputs or the busy/veto outputs.  So I guess I will configure the first two groups to output the trigger primitives and the third group to output the BUSY information.

Added code to do the ADC calibration; added extra equipment for reading out ADC temperatures periodically.

Renewed the lets-encrypt SSL certificate... but haven't set up automatic renewal yet...

[root@ds-proto-daq ~]# certbot renew --apache
[root@ds-proto-daq ~]# systemctl restart httpd

Analyzer program basically working.  Pushed to bitbucket:

https://bitbucket.org/ttriumfdaq/dsproto_analyzer/src

Pierre figured out that NIM crate not working.  We now see LVDS outputs from the individual channels firing. 
Each set of two different channels is ganged together into a single self-trigger output.  By setting the
register 0x1n84 to 3 we enable so that if either input channel fires then the self-trigger for that group fires.

Bryerton provided CDM outputting 50MHz clock; all V1725s now running with external clock.

Modified frontend to readout 4 modules and 16 channels per module.

Still need to modify the analyzer to show data for all 4 modules.

I modified the analyzer so that it shows data from all four modules.

I find that there is evidence of corruption of the V1725 ADC data on a couple channels.   You can see an example of a waveform with corruption in the attachment.  You see that there seems to be a bunch of fluctuations of exactly 16 
ADC counts, which seems unphysical.  So far I see this problem in these channels:

module 0, ch 0
module 0, ch 1
module 0, ch 13
module 1, ch 4
module 3, ch 6

I saw corruption similar to this on the V1730 readout.  CAEN does have a scheme for ADC calibration (by poking a register), which worked well for the V1730.  I thought that I implemented this ADC calibration for the V1725, but I might 
have messed it.  I'll look at this again.

Added pair of 10TB hard-drives in raid-1 to ds-proto-daq.  MIDAS data files will get written to this raid volume.

[dsproto@ds-proto-daq tmp]$ df -h /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/md0        9.1T  180M  8.6T   1% /data
[dsproto@ds-proto-daq tmp]$ cat /proc/mdstat 
Personalities : [raid1] 
md0 : active raid1 sdc1[1] sdb1[0]
      9766435648 blocks super 1.0 [2/2] [UU]
      [>....................]  resync =  0.9% (88214784/9766435648) finish=4372.8min speed=36886K/sec
      bitmap: 73/73 pages [292KB], 65536KB chunk

unused devices: <none>

A little progress on a couple fronts:

1) We got the baseline DAC setting working correctly from both the CAEN command line tool and from the MIDAS
frontend.  Needed to add some extra sleep before the DAC settings were modified.

2) We figured out how to set the threshold for self-triggering on each channel. It is actually register 0x1n60
for this firmware.  The threshold is defined relative to the online calculated baseline. The threshold is
settable from the ODB.  However, the polarity of the triggering is currently hard-coded to be negative (bit 6 of
register 0x1n64).

3) We could confirm that the LVDS outputs from the V1725 appeared and disappeared as expected when the
self-trigger threshold was changed.

4) We added some basic documentation in Markdown here:

https://bitbucket.org/ttriumfdaq/dsproto_daq/src/master/

I added javascript webdisplay of the V1725 waveforms to the Darkside setup.  You can see the waveform display here:

https://ds-proto-daq.triumf.ca/CS/webdisplay

You can also see the webdisplay that comes built into the JSROOT webserver here:

https://ds-proto-daq.triumf.ca/rootana/

For Pierre: I went through and reset the baselines for all the channels.

First check the maximum trigger rate and maximum data rate for different sample lengths (for each channels):

sample length      Maximum rate   MB/s    CPU % (per thread)
16us               0.44kHz        231     20
6.4us              1.04kHz        214     20  
3.2us              1.95kHz        198     22   
1.6us              3.12kHz        160     26   
0.8us              4.88kHz        127     30   (what are these threads doing?)

Look at the code more.  See that there is a maximum size for the block transfer of 10kB.  Increase this to 130kB
(which is the maximum amount that this board can make per event).  Now find

sample length     Maximum rate       MB/s     CPU % (per thread)
16us              0.68kHz            346      7
6.4us             1.46kHz            300      10 
1.6us             3.6kHz             190      25

Good.  So for long samples we are actually slightly above the maximum transfer rate of 85MB/s*4 = 340MB/s

Tried writing out the data to disk at the maximum 345MB/s rate; the DAQ can't keep up.  Maximum rate was more
like 270MB/s.
I think the mlogger was actually fine.  But I think the write-to-disk speed of the harddrive could not keep up.
 So I think we are limited 
by hardware in that case.  We would need a large raid array to be able to write faster.

It turns out that the ZLE V1725 firmware we are using only supports reading out up to 4000 samples per channel.
 We need 80000 samples to readout 200us, which is requirement.

So we switch the V1725s to use the backup firmware on the board, which is the standard waveform firmware. 
Firmware version is 17200410.

Expected data size for event with 200us of data: 200000ns * 1/4 ns/sample * 16 ch * 4 boards * 2 bytes/sample =
 6.4MB per event

Measured max event rate of 60Hz with 385MB/s with 200us readout.

Needed to increase max event size, set buffer organization to 6 and set almost full to 32 in order to
accommodate the larger event size.

Changed some registers for different firmware:
- V1725_SELFTRIGGER_LOGIC

More tests needed

I installed a PCIe 1Gbps network card and configured it as a private network.  The PC (ds-proto-daq) is
192.168.1.1.  I guess we can make the chronobox 192.168.1.2.

[root@ds-proto-daq ~]# ifconfig enp5s0
enp5s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.1  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::bb27:5db:f778:d584  prefixlen 64  scopeid 0x20<link>
        ether 68:05:ca:8e:66:5c  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 27  bytes 4145 (4.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 17  memory 0xf72c0000-f72e0000  

I retested the chronobox trigger generation:

1) Inserting moderate sized pulse into channel 8 of V1725-0.
2) Configured threshold of V1725 so that channel triggers LVDS pulse into chronobox
3) Fan-out trigger out from chronobox to all V1725s.
4) busy signal from each V1725 fed into the chronobox
5) Start run, then push trigger from 20Hz up to 200Hz
6) System running stably!  Actual trigger rate about 60.2Hz.  The almost_full condition is set to 32 on the
V1725s and the estored on each board fluctuates below 32.

https://ds-proto-daq.triumf.ca/HS/Buffers/eStored?hscale=300&fgroup=Buffers&fpanel=eStored&scale=10m

The busy light on the V1725 never comes on, good.

The next thing we need is some way to start/stop the trigger generation on the chronobox, so that at
begin-of-run triggers do not get sent before the V1725s are finished configuration.

Other notes:

a) It turned out that the register to set the V1725 channel trigger threshold was different for RAW vs ZLE
firmware (0x1080 vs 0x1060); after fixing that the channel threshold seemed to work as expected.
b) Map for chronobox NIM cables:

channel 1-4: busy IN from V1725
channel 5,7,8: trigger OUT from chronobox
channel 6: clock OUT from chronobox

Summary of setup of chronobox on network (mostly done by Pierre):

1) Hook up USB connection from chronobox to ds-proto-daq.  Start serial-USB connection by doing

/home/dsproto/online/dsproto_daq/serialusb

can login through serial link.  Added the ssh key for dsproto@ds-proto-daq to the authorized_keys file on
chronobox linux.

ctrl-a, ctrl-x to stop picocom

2) On ds-proto-daq, setup dhcpd server.  Configuration in this file

/etc/dhcp/dhcpd.conf

dhpcd is bond to the second NIC only.  Configure DHCP to give IP 192.168.1.3 to chronobox.  In /etc/hosts set
192.168.1.3 to have hostname chronobox

Power cycle chronobox; it successfully gets IP:

[dsproto@ds-proto-daq dsproto_daq]$ ping chronobox
PING chronobox (192.168.1.3) 56(84) bytes of data.
64 bytes from chronobox (192.168.1.3): icmp_seq=1 ttl=64 time=0.180 ms

3) Can see the chronobox webpage locally as

http://chronobox:8080

4) Some esper tool to access data:  did following to setup esper

  734  yum install python2-pip
  735  pip install esper-tool
  736  yum install ncurses
  738  yum install ncurses-devel
  739  pip install esper-tool

Can then connect to the chronobox by doing

esper-tool interactive http://chronobox:8080

This is as much as I understand at this point... more exploring now...

5) Pierre unplugged the SD card to take it back to Bryerton's room.  But I guess this was bad.

lots of errors on serialUSB link now and the webpage doesn't work anymore:

[ 1246.665269] blk_partition_remap: fail for partition 2
Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.904770] EXT4-fs error: 339 callbacks suppressed
[ 1246.679162] blk_partition_remap: fail for partition 2
Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.904780] EXT4-fs error (device mmcblk0p2):
ext4_find_entry:1437: inode #2: com[ 1246.692884] blk_partition_remap: fail for partition 2
m syslogd: reading directory lblock 0
[ 1246.709020] blk_partition_remap: fail for partition 2
Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.929199] blk_partition_remap: fail for partition 2
[ 1246.717394] blk_partition_remap: fail for partition 2
Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.942971] EXT4-fs error (device mmcblk0p2):
ext4_find_entry:1437: inode #2: com[ 1246.731255] blk_partition_remap: fail for partition 2
m syslogd: reading directory lblock 0
Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.953760] blk_partition_remap: fail for [ 1246.747337]
blk_partition_remap: fail for partition 2
partition 2
Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.967532] EXT4-fs error (device mmcblk0p2):
ext4_find_entry:1437: [ 1246.763481] blk_partition_remap: fail for partition 2
inode #2: comm syslogd: reading directory lblock 0
Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.978320] blk_partition_rem[ 1246.779511] blk_partition_remap:
fail for partition 2
ap: fail for partition 2
Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.992091] EXT4-fs error (device mmcblk0p2): ext4_find[
1246.795586] blk_partition_remap: fail for partition 2
_entry:1437: inode #2: comm syslogd: reading directory lblock 0
Jan  1 00:20:46 buildroot user.warn kernel: [ 1243.002885] blk_[ 1246.811671] blk_partition_remap: fail for
partition 2
partition_remap: fail for partition 2
Jan  1 00:20:46 buildroot user.crit kernel: [ 1243.016656] EXT4-fs error (device mmcblk0p[ 1246.827750]
blk_partition_remap: fail for partition 2

The SDcard is currently required for operation of the device, the ext3/4 filesystem will immediately fail upon removal.


> Summary of setup of chronobox on network (mostly done by Pierre):
> 
> 1) Hook up USB connection from chronobox to ds-proto-daq.  Start serial-USB connection by doing
> 
> /home/dsproto/online/dsproto_daq/serialusb
> 
> can login through serial link.  Added the ssh key for dsproto@ds-proto-daq to the authorized_keys file on
> chronobox linux.
> 
> ctrl-a, ctrl-x to stop picocom
> 
> 2) On ds-proto-daq, setup dhcpd server.  Configuration in this file
> 
> /etc/dhcp/dhcpd.conf
> 
> dhpcd is bond to the second NIC only.  Configure DHCP to give IP 192.168.1.3 to chronobox.  In /etc/hosts set
> 192.168.1.3 to have hostname chronobox
> 
> Power cycle chronobox; it successfully gets IP:
> 
> [dsproto@ds-proto-daq dsproto_daq]$ ping chronobox
> PING chronobox (192.168.1.3) 56(84) bytes of data.
> 64 bytes from chronobox (192.168.1.3): icmp_seq=1 ttl=64 time=0.180 ms
> 
> 3) Can see the chronobox webpage locally as
> 
> http://chronobox:8080
> 
> 4) Some esper tool to access data:  did following to setup esper
> 
>   734  yum install python2-pip
>   735  pip install esper-tool
>   736  yum install ncurses
>   738  yum install ncurses-devel
>   739  pip install esper-tool
> 
> Can then connect to the chronobox by doing
> 
> esper-tool interactive http://chronobox:8080
> 
> This is as much as I understand at this point... more exploring now...
> 
> 5) Pierre unplugged the SD card to take it back to Bryerton's room.  But I guess this was bad.
> 
> lots of errors on serialUSB link now and the webpage doesn't work anymore:
> 
> [ 1246.665269] blk_partition_remap: fail for partition 2
> Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.904770] EXT4-fs error: 339 callbacks suppressed
> [ 1246.679162] blk_partition_remap: fail for partition 2
> Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.904780] EXT4-fs error (device mmcblk0p2):
> ext4_find_entry:1437: inode #2: com[ 1246.692884] blk_partition_remap: fail for partition 2
> m syslogd: reading directory lblock 0
> [ 1246.709020] blk_partition_remap: fail for partition 2
> Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.929199] blk_partition_remap: fail for partition 2
> [ 1246.717394] blk_partition_remap: fail for partition 2
> Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.942971] EXT4-fs error (device mmcblk0p2):
> ext4_find_entry:1437: inode #2: com[ 1246.731255] blk_partition_remap: fail for partition 2
> m syslogd: reading directory lblock 0
> Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.953760] blk_partition_remap: fail for [ 1246.747337]
> blk_partition_remap: fail for partition 2
> partition 2
> Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.967532] EXT4-fs error (device mmcblk0p2):
> ext4_find_entry:1437: [ 1246.763481] blk_partition_remap: fail for partition 2
> inode #2: comm syslogd: reading directory lblock 0
> Jan  1 00:20:46 buildroot user.warn kernel: [ 1242.978320] blk_partition_rem[ 1246.779511] blk_partition_remap:
> fail for partition 2
> ap: fail for partition 2
> Jan  1 00:20:46 buildroot user.crit kernel: [ 1242.992091] EXT4-fs error (device mmcblk0p2): ext4_find[
> 1246.795586] blk_partition_remap: fail for partition 2
> _entry:1437: inode #2: comm syslogd: reading directory lblock 0
> Jan  1 00:20:46 buildroot user.warn kernel: [ 1243.002885] blk_[ 1246.811671] blk_partition_remap: fail for
> partition 2
> partition_remap: fail for partition 2
> Jan  1 00:20:46 buildroot user.crit kernel: [ 1243.016656] EXT4-fs error (device mmcblk0p[ 1246.827750]
> blk_partition_remap: fail for partition 2

a) Bryerton implemented new version of the firmware.  New features:

1) run start/stop state
2) at run start 6 events are sent with 200ms separation
3) there is a greater set of counters about trigger, as well as configuring the trigger.

b) chronobox webpage can be seen here:

https://ds-proto-daq.triumf.ca/chronobox/

The mod_tdm page gives configuration of run state and trigger.  In particular

- button to start/stop run
- button to do manual trigger
- configure which channels are TOP and which are BOTTOM
- configure the number of TOP or BOTTOM channels that need to figure
- DecisionType: true= TOP AND BOTTOM groups must fire; false = TOP OR BOTTOM groups can fire.

c) Start and stop run can also be done on command line with esper tool:

esper-tool write -d true 192.168.1.3 mod_tdm run
esper-tool write -d false 192.168.1.3 mod_tdm run

d) I modified the V1725 frontend to integrate the chronobox start/stop.

At run start
- configure V1725s
- start chronobox with the command-line esper-tool call

At end run
- add deferred transition function which stops run (with esper-tool), then checks whether all the events have
cleared from ring buffers.
- once ring buffers are cleared, finish stopping the V1725s.

In the long run should somehow do the start/stop commands with some http post command, rather than command line
to esper-tool.

e) With the start/stop run could start to compare the timestamps of V1725s and confirm that they matched (ie,
all V1725s got reset at the same time).  Also, all the events are cleared from buffers.

f) However, I found that the frontend program still consistently failed with this error when the trigger rate
was above the maximum sustainable:

Deferred transition.  First call of wait_buffer_empty. Stopping run
[feov1725MTI00,ERROR] [v1725CONET2.cxx:685:ReadEvent,ERROR] Communication error: -2
[feov1725MTI00,ERROR] [feoV1725.cxx:654:link_thread,ERROR] Readout routine error on thread 0 (module 0)
[feov1725MTI00,ERROR] [feoV1725.cxx:655:link_thread,ERROR] Exiting thread 0 with error
Stopped chronobox run; status = 0
Segmentation fault


Next steps:

1) Fix the seg-fault for high rate running.
2) More detailed timestamp checking, with cm_msg(ERRORs)
3) Bryerton is now working on the event FIFO on chronobox.  That will be next thing to integrate.

> f) However, I found that the frontend program still consistently failed with this error when the trigger rate
> was above the maximum sustainable:
> 
> Deferred transition.  First call of wait_buffer_empty. Stopping run
> [feov1725MTI00,ERROR] [v1725CONET2.cxx:685:ReadEvent,ERROR] Communication error: -2
> [feov1725MTI00,ERROR] [feoV1725.cxx:654:link_thread,ERROR] Readout routine error on thread 0 (module 0)
> [feov1725MTI00,ERROR] [feoV1725.cxx:655:link_thread,ERROR] Exiting thread 0 with error
> Stopped chronobox run; status = 0
> Segmentation fault

I sort of 'fix' this problem.  There is some sort of problems between the V1725 readout	thread and the system call
to esper-tools to stop the run.  Some collision between the system resources for these two calls causes the readout
thread ReadEvent call to fail.  I 'fix' the problem by adding in the end_of_run part a 500us pause of the readout
threads before I make the system call to esper-tool.  

Odd.  In principle I think that the system calls and the readout threads are running on different cores.  So not
clear what the problem was.  Should figure out better diagnosis and fix problem properly.

Pierre and I got the CERN proxy setup for the Darkside prototype.

Using your CERN single-sign-on identity, you should be able to login to this page

https://m-darkside.web.cern.ch/

and see our normal MIDAS webpage.

The CERN server is proxying the port 80 on ds-proto-daq.  You can also see all the other services through the
same page:

elog:
https://m-darkside.web.cern.ch/elog/DS+Prototype/

chronobox:
https://m-darkside.web.cern.ch/chronobox/

js-root:
https://m-darkside.web.cern.ch/rootana/


_________________________________

Technical details

1) We followed these instructions for creating a SSO-proxy:

https://cern.service-now.com/service-portal/article.do?n=KB0005442

We pointed the proxy to port 80 on ds-proto-daq

2) On ds-proto-daq, we needed to poke a hole through the firewall for port 80:


firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="188.184.28.139/32" port
protocol="tcp" port="80" accept"
firewall-cmd --reload

[root@ds-proto-daq ~]# firewall-cmd --list-all
public (active)
...
	rule family="ipv4" source address="188.184.28.139/32" port port="80" protocol="tcp" accept

This firewall rule is pointing to some particular IP that seems to be the proxy side of the server:

[root@ds-proto-daq ~]# host 188.184.28.139
139.28.184.188.in-addr.arpa domain name pointer oostandardprod-7b34bdf1f3.cern.ch.

It is not clear if this particular IP will be stable in long term.

3) We needed to modify mhttpd so it would serve content to hosts other than localhost.  So changed mhttpd
command from 

mhttpd -a localhost -D

to 

mhttpd -D

The last elog didn't go out cleanly.  Modified the elogd.cfg to point to the proxy.  Try again.

Notes on day:

1) Fixed the problem with the network interfaces.  Now the computer boots with the correct network configuration; outside world visible 
and private network on.

2) fan tray on VME crate seemed to be broken.  Got another VME crate from pool and installed it.  This VME crate seems to be working 
well. 

3) Recommissioned the DAQ setup.  Found a couple small bugs related to the V1725 self-trigger logic.  Fixed those and the V1725 self-
triggers seem to be working correctly.

4) Tried to install new CDM from TRIUMF (with ssh access), but clocks didn't stay synchronized.  Will bring module back to TRIUMF.

5) Added some code to V1725 frontend for clearing out the ZMQ buffers of extra events at the end of the run.  This is to protect 
against the case where the chronobox is triggering too fast for the V1725s.

Several points:

1) Gave a series of tutorial on DAQ to DS people yesterday and today.  Got a bunch of feedback, which I will pass on when I'm back at TRIUMF.

2) The computer ds-proto-daq was offline when I got in to lab this morning.  Hmm, not clear what is wrong with computer.  Didn't happen the 
first day.  Maybe another power blip?  Maybe we need a UPS for this DAQ machine, to protect it from power blips.

3) Using instructions from Luke, reconfigured the CDM to use the clock from the chronobox. 

4) Added scripts for putting the chronobox and the CDM into a sensible state.  Scripts are 

/home/dsproto/online/dsproto_daq/setup_chronobox.sh
/home/dsproto/online/dsproto_daq/setup_cdm.sh

The scripts need to be rerun whenever the chronobox or VME crate are power cycled.

5) Fix some bugs and added some new plots to online monitoring.  In particular, added a bunch of plots related to the chronobox data.

6) Found some problems with monitoring of chronobox trigger primitives, which I passed onto Bryerton.

I have done a couple longer tests of the DAQ setup.  The runs were done with a high trigger rate of ~60Hz, with
the V1725 asserting their busy to throttle the trigger.

I found that after a couple hours (~5hours) that we would no longer be getting ZMQ packets from the chronobox. 
 You can see this with error message like

15:29:04.092 2019/04/11 [feov1725MTI00,ERROR] [feoV1725.cxx:1033:read_trigger_event,ERROR] Error: did not
receive a ZMQ bank.  Stopping run.
10:26:37.158 2019/04/11 [mhttpd,INFO] Run #657 started

If I start a new run I am still missing ZMQ packets.  However, if I restart the frontend program (and hence
re-initialize the ZMQ link), then the chronobox does start sending triggers again.  So it may be more of a
problem with the ZMQ setup in the MIDAS frontend.  Needs more investigation.

Darkside people seem to be doing some tests at CERN next week.  It looks like they aren't going to use our DAQ (they will I think just use CAEN tools).  But we took 
opportunity to make TRIUMF DAQ work again.  There was a couple issues

1) I needed to inver the busy signal for input 0 to the chronobox in order to get any triggers out of the system.  Not sure why; I don't think I had to do that before.  But it is 
working now.

2) The CERN web proxy was not initially working.  Somehow I 'fixed' it by changing the proxy configuration variable of SERVICE_NAME from 'midas' to 'dummy'.  I don't 
understand why that fixed it.  But now you can see the DAQ here:

https://m-darkside.web.cern.ch/chronobox/