An IO-Link master includes: an IO-Link communication port that communicates with an IO-Link device according to a predetermined communication protocol; a digital input port that receives a first signal value output from the IO-Link device; and a determiner that determines whether abnormality is generated in a digital input line connecting the digital input port to the IO-Link device based on a second signal value received with the IO-Link communication port and the first signal value.

Provided is a highly convenient communication device capable of detecting a communication error caused by an abnormality of a state of communication. A communication device capable of mutually communicating with an electrical device includes: a superimposed signal receiving unit that periodically receives a data signal related to the electrical device as a signal superimposed on an operation signal; a period determination unit that determines whether or not a communication error of the data signal detected by the superimposed signal receiving unit is able to be regarded as having occurred in a transition period of a value of the operation signal; and a state determination unit that determines a state of communication with the electrical device in accordance with the determination by the period determination unit.

Provided is a highly convenient communication device capable of detecting a communication error caused by an abnormality of a state of communication. A communication device capable of mutually communicating with an electrical device includes: a superimposed signal receiving unit that periodically receives a data signal related to the electrical device as a signal superimposed on an operation signal; a period determination unit that determines whether or not a communication error of the data signal detected by the superimposed signal receiving unit is able to be regarded as having occurred in a transition period of a value of the operation signal; and a state determination unit that determines a state of communication with the electrical device in accordance with the determination by the period determination unit.

An IO-Link master includes: an IO-Link communication port that communicates with an IO-Link device according to a predetermined communication protocol; a digital input port that receives a first signal value output from the IO-Link device; and a determiner that determines whether abnormality is generated in a digital input line connecting the digital input port to the IO-Link device based on a second signal value received with the IO-Link communication port and the first signal value.

A device, a fluidic system, a BUS system and a method of operating this BUS system are indicated. The BUS system includes a multitude of users which are producers and/or consumers of at least one process value. Information regarding at least one allocation feature is transmitted to the users of the BUS system by the users of a group of users of the BUS system and by the respective users of the groups themselves. The allocation feature is determined by the at least one process value produced and/or consumed by the respective users.