Abstract: In a method for transmitting data in an HVDCT system to a control system for HVDCT systems, measured values are transmitted from measuring units of the HVDCT system to preprocessing units connected to one another in series. The preprocessing units use the received measured values to generate measured value data. The measured value data are transmitted as part of a data record composed of data words, and the data words are subdivided, during transmission, into a temporal sequence of individual bit groups. A first bit group contains identification data for the preprocessing unit and information on the number of further bit groups that are to be transmitted by the preprocessing unit. A downstream preprocessing unit uses the information on the number of bit groups to be transmitted by a preprocessing unit connected upstream of it to determine a time for transmitting the data word of the downstream preprocessing unit.