Control ======= Almost all configuration of drasi is performed at program startup using the command line options. Some aspects of operation require live control access, which is provided through the :program:`lwrocctrl` program, see :ref:`options `. File writing ------------ File writing can be performed by any node that has been started with the :option:`--file-writer` option, usually an event builder or time sorter. Files can be opened and closed by directing the :option:`--file-open/new/close <--file-open>` requests at the node. Acquisition ----------- While drasi is designed to start and keep the acquisition running as much as possible, it is sometimes needed to stop and start it externally. This is done by directing the :option:`--acq-start/stop <--acq-start>` requests at the master node. Dead-time measurement ~~~~~~~~~~~~~~~~~~~~~ The per-event, per-node, dead-time measurement is started by an :option:`--acq-meas-dt` request to the master node. Since the measurement itself has an small, but non-negligible impact on the acquisition, it only runs for 15 s after start. The results are shown in the monitor tree view.