| 摘要 |
<p>In automatic equipment for the in-circuit testing of board mounting components, it is sometimes necessary to apply guard signals to circuit nodes other than nodes to which a device or gate under test is connected but with which there may be interaction. The invention provides a method for defining guards during the operation of automatic test equipment so that a selected component of a circuit may be tested which method includes the steps of establishing a measurement of the selected component (41) identifying a circuit node associated with the selected component (43), applying a guard to the node (44), establishing a measurement with the selected guard in place (46) and, should the guard result in an improvement, retaining the guard during subsequent automatic testing (48). Improvement may be assessed with respect to an initial unguarded measurement, with or without other guards in place. Those guards showing the greatest improvement may be retained and applied in combination for further improvement. The present invention avoids the need for a highly skilled operator to place guards manually, and also allows assessment of all potential guards which is not practical manually. </p> |
