Abstract: A control system (60) includes a state machine (13, 32) to make a state transition among a plurality of states each set with either of a remote control attribute and a local control attribute as an attribute; and an execution control unit (14, 33) to cause a remote device (30) in a remote environment for a control target device (20) to perform an output value generating process of generating an output value to the control target device (20), when the attribute of a current state of the state machine (13, 32) is the remote control attribute, and to cause a local device (10) in a local environment for the control target device (20) to perform the output value generating process, when the attribute of the current state of the state machine (13, 32) is the local control attribute.

Abstract: A reception unit (221) receives a frame destined for a master located on an upstream side from a slave located on a downstream side. Using a received message authentication code, which is a message authentication code included in the received frame, a concatenation relay unit (230) calculates an intermediate computation result of the received message authentication code. The concatenation relay unit concatenates transmission data, which is to be transmitted to the master, to a transmission data string included in the received frame. The concatenation relay unit calculates a message authentication code for a concatenated transmission data string, using the intermediate computation result. A transmission unit (224) transmits a frame including the concatenated transmission data string and also including the message authentication code calculated using the intermediate computation result, instead of the received message authentication code, to the upstream side.