Special Units

In addition to the standard SI units and Prefixes, SpecMan4EPR accepts a few special units when entering parameter values. They are convenience notations only: the value is converted and stored internally in the standard SI unit of the parameter (for example, seconds for time), so device drivers and saved files never see the special unit.

Unit	Applies to	Meaning	Example
clk	Time parameters (time)	Value expressed in clock periods. The value is multiplied by the current Clock Period and stored in seconds. Useful for clock-coherent hardware (e.g. HDAWG) where pulse widths and delays are naturally counted in clock cycles.	5 clk

Clock unit (clk)

Any time-valued parameter accepts the clk suffix in place of a time unit. It may be used for a single value or throughout a swept range:

Example:

t90 = 5 clk tau = 1 clk to 100 clk step 2 clk

Legend: PPL keywords; PPL pulse commands; comments.

Conversion uses the Clock Period defined in the pulse configuration (Pulse Configurations), which is also stored in the configuration INI under [general] ClockPeriod and recorded into saved experiment files. With a clock period of 2 ns, 5 clk is stored as 10 ns.

Notes:

Values are always stored in seconds. The clk unit affects input and display only.
Display follows the last operand: if the last value in a formula was entered in clk, the parameter is shown in clk form; otherwise it is shown in ns / us.
Parameters are re-evaluated against the current Clock Period when the experiment is validated (on Run). Changing the clock period and pressing Run updates all clk-entered values.
If the Clock Period is set to 0, clk input is disabled.