Ramp Profile
- Gary Cane
Operator Menu Location: Generators
Operator Bitmap:
Functional Description:
The Ramp Profile operator produces a sequence of linear ramps defined by an eleven-point (time, output value) data set:
The operator has two analog inputs x and 
, one digital input p, one analog output y, and one digital output c. Digital input p activates the ramp sequence. While p is LOW, the operator tracks the input, i.e., y(t)=x(t). While p is HIGH, the operator executes the ramp sequence, beginning with the ramp segment where the output value matches the input . That is, the output y of the ramp profile operator is
where 
is a time reference indicating when the ramp sequence begins. If input 
is not connected, then 
is equal to the instant that digital input p switches to high (i.e., 
). Otherwise, if input 
is connected, then the time reference 
is determined from:
for the smallest index i[0,9] that satisfies either 
or 
. If no such index exists (i.e., if 
and 
) then the entire ramp sequence is executed (i.e., ).
Digital output c indicates when the ramp sequence is complete. It is defined by
Consider the property sheet shown to the left for a sample ramp profile operator. When input p activates the operator, the portion of the ramp sequence that will be executed will depend on the value of input 
at the activation time.
If input 
is not connected then the entire ramp sequence will be executed, as shown in the figure below. The entire sequence will also be executed if input is outside of the ramp range (i.e., if 
or 
).
When input 
is connected, the operator will begin the ramp sequence with the first output value matching 
. For instance, when 
, the ramp output will begin with the fourth segment of the ramp sequence (skipping the first 22.5 seconds).
And when 
, the output will begin with the seventh segment of the ramp sequence (skipping the first 46.77 seconds).
User-Defined Properties:
Object Name. A string label that identifies the operator
Display Ramp Start. This property determines if output pin 
is visible in the schema diagram. Design Pad issues a warning upon processing the schema when the pin is visible but not connected. The warning message is not issued when the pin is not visible (when this property is not checked).
Display Completion. This property determines if output pin 
is visible in the schema diagram. Design Pad issues a warning upon processing the schema when the pin is visible but not connected. The warning message is not issued when the pin is not visible (when this property is not checked).
. First (time, output value) data pair in ramp sequence
. Second (time, output value) data pair in ramp sequence
…
. Last (time, output value) data pair in ramp sequence
Comments:
•The time coordinates must be non-negative and may not exceed 8,388 seconds (139.8 minutes), i.e., 
•The time coordinates of the ramp sequence must be monotonically increasing, i.e., 
•Output y will be discontinuous if 
See Also: Characterizer