getLoopTransfer - Class: slTunable

location

String or cell array of strings specifying signal locations at which to compute a point-to-point open loop transfer function. Each signal in location must be present in the Switches, Controls, or Measurements properties of the slTunable interface ST. Use a cell array to specify multiple locations and compute a MIMO loop transfer.

You can specify an abbreviated signal path in location provided the string matches the end of the full signal path and unambiguously identifies the signal.

sign

Sign of the open-loop transfer function L.

• +1 (default) — getLoopTransfer returns the positive-feedback open-loop transfer function, computed by injecting sine waves at the locations specified in location and measuring the return signals at the same point. The closed-loop transfer function is feedback(L,1,+1).

• -1 — getLoopTransfer returns the negative-feedback open-loop transfer function. The negative-feedback transfer function is –1 times the positive-feedback transfer function. The closed-loop transfer function is feedback(L,1).

Set sign to -1 if you intend to use the open-loop transfer function L in applications that assume the negative-feedback definition of L. Many classical design and analysis techniques use the negative-feedback convention. For example, the Nyquist or root locus design techniques usually assume that L is defined such that the closed-loop transfer function is feedback(L,1).

Default: +1

openings

String or cell array of strings specifying additional locations at which feedback loops are opened for the computation of L. Specify the locations as the names of signals listed in the Controls, Measurements, or Switches properties of ST. Loop openings listed in the Openings property of ST are always open.

You can specify an abbreviated signal path in openings provided the string matches the end of the full signal path and unambiguously identifies the signal.

Default: {0x1 cell}