In a numerical control system in which a numerical controller is connected with a plurality of amplifiers via a daisy-chain serial bus, these amplifiers are grouped into a first group and a second group, and connected in an order of the amplifiers of the first group and the amplifiers of the second group from the numerical controller. Further, a communication cycle in the communication between the numerical controller and the amplifiers of the second group is set n times (n is an integer of 2 or larger) as large as a communication cycle of the first group.

A process control arrangement (PKA), having a number of fieldbus systems (DP1, PA1, FH), especially different fieldbus systems (DP1, PA1, FH), and having a number of fieldbus interfaces (PAP1, PAP2, PAP3), wherein each of the fieldbus systems (DP1, PA1, FH) is connected to at least one of the fieldbus interfaces (PAP1, PAP2, PAP3), wherein the fieldbus interfaces (PAP1, PAP2, PAP3) serve for communication between the fieldbus systems (DP1, PA1, FH) and a communication plane (ET2) superordinated to the fieldbus systems, only a first of the fieldbus interfaces (PAP1) is directly connected to the superordinated communication plane (ET2), and wherein the fieldbus interfaces (PAP1, PAP2, PAP3) are connected in series with one another beginning with the first of the fieldbus interfaces (PAP1).