Channels Dialog

The Channels dialog is opened from the Dialog menu, or from the context menu on the Responses listbox in the Setup and Results modules. In the Setup module, the Channels dialog is used for selecting the reference and response channel sieves used in signal processing. In the Results module, the Channels dialog has reduced functionality, as it is not used for sieving but only for selecting the responses for plotting.

The channels are listed in the table by their Channel or Index, Response Coordinate, ID Line 1, and Data Type. For the Setup module Channels dialog, the Channel does not necessarily correspond to the data acquisition system channel number, but is actually the record in the file or index of the imat_fn. For the Results module Channels dialog, the Index corresponds to the row of the frequency domain function matrix, which could be different from the channel number, accounting for channels disabled for signal processing.

Clicking on a column header sorts the table by that attribute. The rows of the table can be selected with the mouse. The Invert button inverts the current selection of rows. Clicking in the table and pressing Ctrl+A selects all rows. The Disable button disables the selected channels, and the Resp button makes those channels responses. Checking a box in the Ref column makes that channel a reference. Checking a box in the Basis column makes that channel an Hd FRF basis. The disabled channels are displayed as gray text in the table and the enabled channels as black text. The Apply button will apply the current sieve of reference, response and disabled channels. The Cancel button will close the dialog without applying the sieve. The OK button will apply the current sieve and close the dialog. The Plot button will plot the selected channels.

The channels in the table can be filtered by several attributes: Channel or Index, Response Coordinate (node number and direction), Response Node, Response Direction, ID Line 1 (text description), Data Type or Coordinate Trace. For Channel, Index and Response Node, enter a numeric value in the edit box. The MATLAB array notation (e.g., 1:100) is supported, with an exception that the increment notation (e.g., 1:2:100) is not supported for Response Node. For Response Coordinate and ID Line1, enter a text string in the edit box. The asterisk ('*') wildcard character is supported. For Response Direction, Data Type, and Coordinate Traces, select from the popup list menu.

To filter the channels: (1) select the type of table rows on which to filter (i.e., 'All', 'Selected', 'Enabled', or 'Disabled'); (2) select the filter attribute; (3) enter or select the value for the attribute; and (4) push the Filter button. Those channels meeting the filter criteria are selected, and then those channels can be made responses or disabled. The filter can operate on 'All' table rows or on the table rows that are 'Selected' (highlighted), 'Enabled' (response channels), or 'Disabled' (disabled channels). The reference channels are ignored by the filtering.

The Coordinate Traces available for the Channel dialog filter are those that were loaded into spFRF from a Universal file or from the MATLAB workspace. New coordinate traces can also be created from the current responses sieve (i.e., those responses that are enabled) with the CTrace button. An input dialog is presented to enter the name of the created coordinate trace. The created coordinate trace is appended to any existing coordinate traces. The coordinate traces can be saved to a Universal file or the MATLAB workspace from the File menu.