SICS counter handling
A counter in SICS is a controller which operates single neutron
counting tubes and monitors.
A counter can operate in one out of two modes: counting until a timer has
passed,
for example: count for 20 seconds. Counting in this context means that the noutrons coming in during these 20 seconds are summed together. This mode is called timer mode. In the other
mode, counting is continued until a specified neutron monitor has
reached a certain
preset value. This mode is called Monitor mode. The preset values in Monitor
mode are usually very large. Therefore the counter has an exponent data variable.
Values given as preset are effectively 10 to the power of this exponent. For
instance if the preset is 25 and the exponent is 6, then counting will be
continued until the monitor has reached 25 million. Note, that this scheme with
the exponent is only in operation in Monitor mode.
Again, in SICS the counter is an object which understands a set of
commands:
- countername setpreset val sets the counting preset to val.
- countername getpreset prints the current preset value.
- countername preset val With a parameter sets the preset, without inquires the preset value. This is a duplicate of getpreset and setpreset which has been provided for consistency with other commands.
- countername setexponent val sets the exponent for the counting
preset in monitor mode to val.
- countername getexponent prints the current exponent used
in monitor mode.
- countername setmode val sets the counting mode to val. Possible values are Timer for timer mode operation and Monitor for waiting for a monitor to reach a certain value.
- countername getmode prints the current mode.
- countername mode val With a parameter sets the mode,
without inquires the mode value. This is a duplicate of getmode and
setmode which has been provided for consistency with other
commands. Possible values for val are either monitor or timer.
- countername setexponent val sets the exponent for the counting
preset in monitor mode to val.
- countername getcounts prints the counts gathered in the last run.
- countername getmonitor n prints the counts gathered in the monitor number n in the last run.
- countername count preset starts counting in the current mode and the given preset.
- countername status prints a message containing the preset and
the current monitor or time value. Can be used to monitor the progress of
the counting operation.
- countername gettime Retrieves the actual time the counter
counted for. This excludes time where there was no beam or counting was
paused.
- countername getthreshold m retrieves the value of the threshold set for the monitor number m.
- countername setthreshold m val sets the threshold for monitor m to val. WARNING: this also makes monitor m the active monitor for evaluating the threshold. Though the EL7373 counterbox does not allow to select the
monitor to use as control monitor in monitor mode, it allows to choose
the monitor used for pausing the count when the count rate is below the
threshold (Who on earth designed this?)
- countername send arg1 arg2 arg3 ... sends everything behind
send to the counter controller and returns the reply of the counter
box. The command set to use after send is the command set documented
for the counter box elsewhere. Through this feature it is possible to
diretclly configure certain variables of the counter controller from
within SICS.