STOP Command

Background

The stop command was invented to allow users to stop a data acquisition in mid-stream. There are a variety of reasons for wanting to do so:

• Malfunction of other subsystems at the telescope
• Not receiving any DV pulses from the Sync Box

The cmd_translator block on the clock card is the block that nominally runs data acquisitions. It is a complicated piece of code, and requires simulation of the following cases to verify it fully:

• Acquisition of one frame of data
• Acquisition of multiple frames of data
• Acquisition while sourcing the DV from the Sync Box (use_sync=2, use_dv=2, select_clk=1)
• Acquisition while sourcing the DV from the Sync Box's input (use_sync=2, use_dv=2, select_clk=1)
• Acquisition while sourcing the DV from the Sync Box and disconnecting the Sync Box fibre.
• Acquisition while sourcing the DV from the Sync Box with the fibre initially disconnected
• In all of the scenarios above, a Stop command should allow the MCE to recover