GE PACSystems RXi User Manual

Chapter 6. Program Organization102 PACSystems* RXi Distributed IO Controller User Manual GFK-2816FUsing Parameters with a Parameterized BlockA parameterized block may be defined to have between 0 and 63 formal input parameters,and between 1 and 64 formal output parameters. A ‘power-flow out’ (or OK) parameter,named Y0, is automatically defined for every parameterized block. It is a BOOL parameter ofLENGTH 1, and indicates the successful execution of the parameterized block. It can be readand written to by the parameterized block’s logic.The following table lists the TYPEs, LENGTHs, and parameter-passing mechanisms allowedfor parameterized block parameters. (For definitions of the parameter passing types, refer toSection 6.1.7, Parameter Passing MechanismsICRXICTL000, GFK-2816, GFK2816.)Type Length Default Parameter Passing MechanismBOOL 1 to 256 INPUTS: by referenceOUTPUTS: by value result; except Y0, which is by initial-valueresultBYTE 1 to1024INPUTS: by referenceOUTPUTS: by referenceINT, UINT, and WORD 1 to 512 INPUTS: by referenceOUTPUTS: by referenceDINT, REAL, andDWORD1 to 256 INPUTS: by referenceOUTPUTS: by referenceLREAL 1 to 128 INPUTS: by referenceOUTPUTS: by referencefunction block3 1 INPUTS: by referenceOUTPUTS: not allowedUDFB3 1 INPUTS: by referenceOUTPUTS: not allowedUser Defined Type(UDT)1 to1024INPUTS: by referenceOUTPUTS: not allowedThe PACSystems default parameter passing mechanisms correspond to the way thatparameterized subroutine block (PSB) parameters are passed on 90-70 controllers. Theparameter passing mechanisms of formal parameters cannot be changed from their defaultvalues.3 A maximum of 16 input parameters can be of type function block or UDFB.