Ramp Generator

• The MCE can be set to write values to internal registers. For arbitrary shapes, see [ Arbitrary Waveform Generator ].
• Setup for simple ramps is similar to the setup for arbitrary waveforms.

Commands and Usage

• Commands:
  • internal_cmd_mode (0xB0): Enable or disable internal housekeeping/ ramping commands. Default = 0.
    • mode = 0: Disable internal commands
    • mode = 1: Enable Housekeeping commands
    • mode = 2: Enable ramp commands
    • mode = 3: Enable arbitrary waveform (AWG) commands
  • ramp_step_period (0xB1): Specify the number of frame periods between each ramp step.
  • ramp_param_id (0xB5): Specify the parameter ID of the register to be ramped.
  • ramp_card_addr (0xB6): Specify the card address of the register to be ramped.
  • ramp_step_data_num (0xB7): Specify the number of data that are to be written per ramp command.

• Usage:

wb cc internal_cmd_mode 0    # Disable internal commanding
wb cc ramp_step_period 10    # Period, in internal MCE frames.  Don't go too low here.
wb cc ramp_card_addr 2       # Card id (Clock Card, for example)
wb cc ramp_param_id 0x99     # Parameter id (LED, for example)
wb cc ramp_step_data_num 1   # 

wb cc internal_cmd_mode 3    //Enable internal AWG commands AFTER writing the data!!!

wb cc data_rate 10
wb cc ret_dat_s 1 1000
go cc ret_dat 1

Firmware Details

• Implementation:
  • To enable the AWG internal commands, you set internal_cmd_mode = 3, as shown in the usage, above.
  • The AWG value is applied immediately following a data packet, and appears in index 7 of the next data-packet header. This index is called "Ramp Value", and is also used to report the ramp value when the MCE is in internal ramp mode (internal_cmd_mode = 2)

• Commands of note:
  • internal_cmd_mode
  • ramp_step_period
  • ramp_min_val
  • ramp_step_size
  • ramp_max_val
  • ramp_param_id
  • ramp_card_addr
  • ramp_step_data_num