Help on Message 34:4374
Des cription of Error:

P# may only be used as address operator for local symbols of the uppermost structure level (parameter level). Otherwise these address constants could in many cases (such as nested function (FC) parameters) become too big for the MC7 register.

同意youhm的说法，西门子编译器不支持这种写法而已。
http://support.automation.siemens.com/WW/view/en/22422092