PacsOne Server

The software of our Siemens CT unfortunately has only a single entry field for the whole patient name. Therefore our staff enters the patient name in a format like "Smith John" or "Smith,John" (without quotation marks).
An examination of PacsOne logfiles and of table patient in MySQL shows that PacsOne stores the whole string in field lastname whereas the field firstname remains empty.
Is there a way to tell PacsOne that Smith is the lastname and John is the firstname?

PacsOne does not have control over how the firstname and lastname are encoded. It is the sending application (Siemens CT in your case) that controls how to encode the firstname and lastnames.

In your given example, the real name "John Smith" or "Smith, John" should be encoded as Dicom PersonName VR string "Smith^John" (without quotes) by your Siemens CT, so that when PacsOne receives the data it could correctly saves "Smith" as the lastname and "John" as the firstname from the Dicom formatted person name string.

However, if the Siemens CT encodes the same name as "John Smith" or "John Smith^" in Dicom formatted person name, then PacsOne would parse the Dicom formatted person name into "John Smith" as the lastname and firstname being empty.

In other words, the person names are solely decided by the encoding application, PacsOne is merely a receiver that tries to interpretate the names from the Dicom formatted person name string, so PacsOne really has no control over how the names got written.

If the encoding application does not adhere to the Dicom standard when encoding person names, then all Dicom applications trying to interpretate the non-conforming person names will have problems parsing the names thus will yield inconsistent names.