This function is used by default. It prints a message asking the operator to manually trigger a flash. A more elaborate function, using specific hardware can be used to automatically trigger a light source or some other synchronized event such as releasing the shutter of a camera.
Note
When using this function, set an integration time that gives enough time for the manual triggering of the flash to reliably fall within the integration.
See also
Sys.sleep for a description of the variation
in the effective duration of the delay.
Other interactive acquisition utility functions:
choose_ch_interactive(),
choose_sr_interactive(),
list_srs_interactive(),
protocol_interactive(),
set_attributes_interactive(),
set_folder_interactive(),
set_seq_interactive(),
set_session_name_interactive(),
set_user_name_interactive(),
set_wlrange_interactive(),
tune_interactive()
