Appendix A: Helper Software

The subversion/git repository contains some software packages which can be used to decode the bunches in the UDP packets received from the TiCkS. All of these may be re-implemented in whatever code the users prefers, of course.

  • TiCkS_decode: contains the routines for:

    • Decoding a bunch into individual events

    • Printing individual events or writing them to file in CDTS structure, and checking for errors

    • Reading in a configuration xml file

  • TiCkS_standalone: main routine and Makefile (with some example configs) for:
    • Receiving UDP packets from a TiCkS at a given IP / Port,

      or all TiCkS at a given Port by calling the routines in TiCkS_decode

    • Depending on the options in the configuration XML (given on command line)

      • Prints events to stdout and/or writes to file

      • Prints errors to stdout or stderr, or none

      • Prints a debug dictionary of delta Event/Busy/Time to stdout

      • Optionally correct skipped event counters

  • cdtsServerSimulator:
    • Receives UDP packets from a TiCkS at a given IP / Port, or

      all TiCkS at a given Port by calling the routines in TiCkS_decode

    • Connects to cameraServer (address given in the configuration XML on command line), and sends event in TCP/IP packets

    • If the option is chosen in the configuration XML (given on command line), prints errors to stderr

    • Optionally correct skipped event counters

Some details

  • Debugging lines with printing to stderr or stdout (user choice) of:

    • Events with busyFlag != busyBit

    • Events with SPI time-out

    • Events with non-monotonic event counter increase (sum of read-out + busy counters)

    • Possibility to apply error correction for non-monotonic event counter increase, if this is within a margin of error

    • (i.e. lost packets will give big jumps, which should not be corrected)

  • Technical detail, the software will work correctly even for multiple TiCkS sending to a IP on multiple ports, or sending to the same port on multiple IPs

    • This is done by using a “ulhash” hash table to keep previous values of counters, timestamps for the given TiCkS IP/Port combination… a very nice and widespread package!

  • Configured by some values in in the config xml file (but with a default to 0 for integer values), err_output and cor_margin

    • see example below

  • Completely replaced mini-xml by libxml2

    • much more standard than mini-xml (and is used by gnome)

    • easier to configure with “xml2-config” command in the Makefile

  • !!! With change from mini-xml to libxml2, must add top level enclosure tags

  • Moved getConfigurationFromXmlFile to TiCkS_decode

    • makes this much easier to call from other codes

Configuration XML file example:

<?xml version="1.0" encoding="UTF-8"?>
<configs>

<cdts_server_address>10.10.3.250</cdts_server_address>
<cdts_server_port>55501</cdts_server_port>

<!-- Next two lines are ignored by ticks_standalone -->
<camera_server_address>10.10.3.250</camera_server_address>
<camera_server_listen_port>12345</camera_server_listen_port>

<!-- Note, if ucts_address is left blank, or missing, all UCTSs on the port will be received
<ucts_address>10.10.3.99</ucts_address>
<ucts_address /> -->

<!--Event Types: 0 for all, 1 for read-out, 2 for busy-->
<event_types>0</event_types>

<!-- Use logical values for the next three (0 = False) -->
<print_event>0</print_event>  <!-- ATTENTION, can get lots of output to stdout ! -->
<file_event>0</file_event>  <!-- gets ignored for cdtsServer, no file output for now -->
<dict_debug>0</dict_debug>

<!-- This is where the error output should go:
  * 0 is stderr
  * <0 for no output
  * >0 for stdout (changed to 6, then) -->
<err_output>0</err_output>  <!-- gets overridden to 0/stderr for cdtsServer -->

<!-- Margin within which to correct counters
  * <=0 for no correction
  * small number, to correct but avoid correcting if packets lost -->
<cor_margin>0</cor_margin>

<ts_data_path>../TiCkS_data</ts_data_path> <!-- gets ignored for cdtsServer, no file output for now -->

</configs>

Notes:

  • Any node which isn’t defined is set to a sensible default value

  • The first two nodes have to be there, with relevant values

  • To receive several TiCkS at once

    • then either send them to the same port and leave ucts_address blank

    • or send them to the same ucts_address and the same port

  • Normal operation so far is to execute each cdtsServer with a dedicated Port all on the same machine

    • This fits well with the paradigm of having the cdtsServer being part of the camera

    • In this paradigm, it should run on the Camera Server machine, and send its UCTS-timeStamp events to the SWAT

    • Optionally sending UCTS-timeStamp events to the Camera Event Builder in parallel