An apparatus for carrying out serial control includes a single main controller and a plurality of node controllers for directly controlling a variety of sensors and actuators. The node controllers are serially connected to the main controller. The main controller receives a data signal row which is successively transferred through the node controllers and then indirectly and centrally controls sensor data derived from the sensors, as well as actuator control data transmitted to the actuators. Data is transmitted from the data signal row to the sensors or the actuator to be controlled and vice versa in each node controller. An error code is added to the data signal row which is to be transferred to a succeeding port under logic conditions indicating the occurrence of an error. The occurrence of an error is confirmed by inspecting an error check code which is previously added to the data signal row to check whether an error has or has not occurred between the node controllers. The error code for indicating the occurrence of error is added to the data signal row which is inputted into the relevant node controller.