Mike, That's news to me... Could you back this up from the spec or any BIRDs? Common sense tells me that you can only make a selection if you have multiple items to pick from. First, with Usage Out parameters the EDA tool doesn't anything into the AMI model, so the model has nothing to select from. Second, even if we pretend that a Usage Out parameter supposed to be treated as if it was Usage InOut, where the EDA tool passes something to the model and the model returns something in response, when it comes to multi valued parameters, such as Range, List, Increment and Steps, the EDA tool can only pass one value to the AMI model in the AMI_parameters_in string, so the model can still not make a selection from multiple items. (The only way a model can get multiple values is through Table...). This is based on BIRD 127.4: |* The EDA tool must process the content of the .ami file so that |* 1) the 'Reserved_Parameters' and 'Model_Specific' branch |* names and their associated open and close parentheses "()" |* are not included in the AMI_parameters_in string, and |* 2) the AMI Parameter branches with Usage In or Usage InOut |* are converted to leaf/value pairs for the AMI_parameters_in |* string, possibly incorporating user selections. In this |* conversion each AMI parameter branch name becomes a leaf |* name in the AMI_parameters_in string and each leaf name |* is followed by a white space, a value and a closing |* parentheses ")". Note: #1) that "The EDA tool must process the content of the .ami file", which indicates to me that the selection of one value from multi valued parameters is done by the tool, not the model. #2) that "each leaf name is followed by a white space, a value" where value is singular, so the model has nothing to select from. #3) the phrase "possibly incorporating user selections", indicates to me that the multi valued parameters are reduced to a single value either by the user making a selection or the rules revolving around using <typ> or Default. This is why Default to me refers to the selection mechanism and not to initializing variables in the EDA tool and/or the AMI model. Your understanding or interpretation of the spec and BIRDs seems to be quite different from the way I read them... Thanks, Arpad ============================================================ From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Steinberger Sent: Friday, December 16, 2011 12:33 PM To: ibis-macro@xxxxxxxxxxxxx Subject: [ibis-macro] Re: Usage Out syntax rules Arpad- The model makes the selection for parameters of Usage Out. Mike S.