I assume your text deals with pick-and-place robots used to convey (transfer tool) parts to be pressed (Pressteil). The Ablagehöhe refers to the Z-axis height (see 1st ref below) from, I assume, the base of the Unterlage to the top of the open tool (geöffneter Werkzeug - Heber oben). The text says that all the parts must maintain equal deposit height (the part is "deposited" by the robot onto a table, platen, another tool, etc. - details from your text) so that they don't hit the Heber or the Unterlage. Once the part is deposited in the right position (correct Ablagehöhe), the pressing takes place and then it's moved to the next Werkzeugstufe. (all this I take from many many very similar projects I've worked on in injection molding and car parts assembly).

The PDF file is a great ref on moulding robotics. Do google searches on 'pressing - molded parts - tool - heights'