Register specifications

Within the telviewer program, registers can be displayed graphically or textually. They can also be subsequently read from the archive using the read_registers program, or the python readarc module.

Each register that is to be displayed in telviewer or read from the archive, needs to be specified at some point. Registers are specified either textually, or via pull-down menus. Each textual register specification starts with the name of the system that monitors the register. The system name is followed a period and the name of the sub-system that the register belongs to. The subsystem name is followed by another period, and the name of the register within the specified subsystem. Finally, if the register is an array, then an element or range of elements can be specified, enclosed in square brackets.

The following is a list of the valid register specifications. Note that for historical reasons, subsystems are refered to as "board"s.

• system.board.name (eg. mount.weather.air_temp)

  This refers to all of the elements in a register called name on the board named board, which is monitored by the system named board. The example specification would select the air-temperature register, which is a register that belongs to the weather subsystem of the mount control system.

• system.board.name[index] (eg. mount.tracker.axis_offsets[0])

  This selects array element index of the system.board.name register. The example specification would select the first element (0) of the two element axis_offsets[] register, which belongs to the tracker subsystem of the mount control system.

• system.board.name[index1-index2] (eg. kuband.rx.vg[0-2])

  This selects all array elements between index1 and index2 of the system.board.name register. The example specification would select elements 0,1 and 2 of the gate-voltage register of the receiver subsystem ofthe kuband control-system.

• system.board.name.aspect (eg. mount.frame.utc.time)

  This selects all elements of the system.board.name register after combining neighboring pairs of elements to form the type of value specified by aspect. This can only be used with complex, and utc registers. The example specification would select the UTC time of the two element utc date/time register, which belongs to the register-frame subsystem of the mount control system.

  UTC Register Aspects

  The following combinational aspect names are supported for registers that contain the date and time in Universal coordinated time. By convention all such registers are named system.board.utc.
  • date - The Modified Julian Day number part of the register (eg. mount.frame.utc.date).
  • time - The time part of the register in hours (eg. mount.frame.utc.time).

  Complex Register Aspects

  The following combinational aspect names are supported for complex registers. Note that at the time of writing this help page, none of the instruments had any complex registers.
  • real - The real part of a complex pair of register elements.
  • imag - The imaginary part of a complex pair of register elements.
  • amp - The amplitude of a complex pair of register elements.
  • phase - The phase of a complex pair of register elements.

• system.board.name.aspect[index]

  This selects the index'th pair of register elements after they have been combined as described above for system.board.name. Thus system.board.name.amp[3] selects the amplitude of the complex register pair (system.board.name[6],system.board.name[7]).

• system.board.name.aspect[index1-index2]

  This selects the index1'th to index2'th pairs of register elements after they have been combined as described above for system.board.name.