Interacting with the SinqHM software
The server side software on the histogram memories is actually a WWW-server. It not only
serves SICS to do its job but it also has a nice WWW interface which allows to debug
neutron data acquisition from a WWW browser. This document details how to do this and which
information can be gained.
Connecting to the SinqHM WWW-server
A little bit complicated due to firewalls etc.
- Log in to the instrument computer
- Find the name of the HM computer, often it is insthm, like for example amorhm. See
/etc/hosts for names
- Point your WWW-browser, running on the instrument computer to that HM computer.
- You should be on the SinqHM WWW-interface now
- At some places SinqHM asks for user credentials: these are spy/007
The SinqHM Status Page
Choose the status tab on the WWW interface. You get a page like below from which some things can already
There is this line reading: Events processed by filler When DAQ is active, the associated number
should increase continuously. Even with SINQ off there should be events any few seconds. If
nothing is coming here, then the electronics does not send neutron events.
The next line reading Events skipped due to mask is interesting too. This will continuously
increase when the HM sees events where the sync bits are not OK. A small percentage of all neutron
events occuring here is OK. But if all events come here, something is wrong. Scroll down further, and
you can see which sync bit is triggered. But there is only a channel number. What is plugged in
there, ask the electronics guys.
Then there is a line or lines reading something like:
bank 0: axis 1: counts low: 0 counts high: 0
Such lines show if there are events outside of the histogramming limits for this axis.
For normal, physical detector axis like x or y, this should be low numbers of neutron events,
ideally 0. If this is not the case, something is wrong: either the electronics delivers phony
numbers of the configuration of the HM is wrong. Check the configuration page.
For TOF axes it is normal that some percentage of the neutron events are outside of the
time binning range. But if a large number of events is outside, scold the user because she
configured an unsuitable time binning.
If any of the counters: Events unknown, Packets incomplete or Packets oversized keeps increasing,
then the electronics is sending bad packets on the fibre optics link. After SINQ startup this might
actually have a high count, when there is no electronics switched on or if the fibre optics link
is disconnected this increases too. Due to noise. To be sure, reboot the HM and observe what
Then there is the counter with the TSI packets. TSI packets are Time Status Information packets which
are sent by the MDI at regular time intervalls. They contain status information from the electronics.
No matter what, this counter should increase slowly over time. If not, the detector electronics is
either switched off or broken. In the latter case, raise an alarm with electronics guys. This is no longer
a software problem.
There are other counters here: Detected Fifo Overflows, Detected Taxi Chip Errors. If these
increase, either the fibre optic link has been disconnected or the Mezanine card for reading
the fibre optic link into the HM is broken. Again a problem for the electronics group; not
The Configuration Page
This page shows the current configuration as known to the HM. It may be useful to look at this
when there is the assumption that the configuration is not properly transferred by SICS. BTW: if there
is such a problem: SICS compiles the XML configuration with a script. The script name can be found by
looking at the initscript parameter of the HM in SICS.
The Debug SHM Tab
This page shows error messages from the HM software itself. There is rarely something intersting to be
found here: the HM software is stable since years.
The Raw Data Tab
From this tab, it is possible to look at the raw neutron event messages as they come in from the fibre optic
link. This is sometimes useful for debugging purposes. When you enable Show Packet Info, the packest will
be unpacked into a readable form. Otherwise interpreting the packets is a binary black art
especially as there is not much documentation about the packet format besides the source code of
the SinqHM software. Please note: the WWW-interface works best with firefox; events will only be shown
after restarting DAQ.
This page last changed on 04-Jul-2014 14:08:39 CEST by MarkKoennecke.