## Documentation Center |

To obtain an open-loop transfer function from a model, you specify
a loop opening. Loop openings affect only how the software recombines
linearized blocks, not how the software linearizes each block. In
other words, the software ignores openings when determining the input
signal levels into each block, which influences how nonlinear blocks
are linearized. Consider the following model, where you obtain the
transfer function from `e2` to `y2`,
with the outer-loop open at `y1`:

Here, *k _{1}*,

The software linearizes each block at the specified operating
point. At this stage, the software does not break the signal flow
at `y1`. Therefore, the block linearizations include
the effects of the inner-loop and outer-loop feedback signals.

*K _{1}*,

Finally, to compute the transfer function, the software enforces
the loop opening at `y1`, injects an input signal
at `e2`, and measures the output at `y2`.

The software returns (*I*+*G _{2}*

`addOpening` | `getCompSensitivity` | `getIOTransfer` | `getLoopTransfer` | `getSensitivity` | `linearize`

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