Abstract: A safety device of the invention includes at least one of an input unit having one or more input terminals and an output unit having one or more output terminals, a testing unit having one or more test terminals, a rewritable nonvolatile memory configured to store setting information of a terminal specification which can be set from outside via the tool, and wherein the terminal specification of the one or more test terminals included in the testing unit is determined in accordance with the setting information of the terminal specification.

Abstract: This invention provides an input device of safety unit which enables an error diagnosis result referred to in a process of input processing for generating a control data from raw input signal to be referred by a side using the control data also in a safety unit such as a safety master and safety slave. An input device contains a function of outputting status data indicating the error diagnosis result referred to when input signal is converted to control data and the control data obtained by the conversion in pair, so that when the logical value of the control data is “LOW”, whether it originates from that the raw logical value is “LOW” or that “LOW” is compulsorily set due to an error in the terminal can be determined from the logical value of the status data.

Abstract: A network system for carrying out communication between a control station and a plurality of devices connected to a network. The communication includes data communication which requires real-time attributes and message communication which does not require real-time attributes. The data communication includes a first data communication, and a second data communication. The system includes a plurality of transmission queues for temporarily storing transmission data provided in the control station, wherein one of the queues holds transmission data for the second communication. After the first data communication is carried out in accordance with a predetermined cycle time, an appropriate switching between the message communication and the second communication is carried out in the remaining time of the cycle time to complete one cycle, whereafter the cycle is repeatedly carried out.

Abstract: This invention provides an input device of safety unit which enables an error diagnosis result referred to in a process of input processing for generating a control data from raw input signal to be referred by a side using the control data also in a safety unit such as a safety master and safety slave. An input device contains a function of outputting status data indicating the error diagnosis result referred to when input signal is converted to control data and the control data obtained by the conversion in pair, so that when the logical value of the control data is “LOW”, whether it originates from that the raw logical value is “LOW” or that “LOW” is compulsorily set due to an error in the terminal can be determined from the logical value of the status data.

Abstract: A safety device of the invention includes at least one of an input unit having one or more input terminals and an output unit having one or more output terminals, a testing unit having one or more test terminals, a rewritable nonvolatile memory configured to store setting information of a terminal specification which can be set from outside via the tool, and wherein the terminal specification of the one or more test terminals included in the testing unit is determined in accordance with the setting information of the terminal specification.

Abstract: A network system for carrying out communication between a control station and a plurality of devices connected to a network, wherein such communication includes data communication which requires real-time attributes and message communication which does not require real-time attributes, and wherein the data communication includes a first data communication in which data is transmitted from the control station to the devices and data in response to this transmission is transmitted from the devices to the control station, and a second data communication in which data is transmitted from the control station at a prescribed timing, includes a plurality of transmission queues for temporarily storing transmission data provided in the control station, wherein one of the queues holds transmission data for the second communication; wherein after the first data communication is carried out in accordance with a predetermined cycle time, an appropriate switching between the message communication and the second communicati

Abstract: A local area network system in which a logical ring is formed by at least part of said node stations to pass a token frame from one station to another in an endless and cyclic fashion allowing each of said node stations which has received is allowed to transmit data, and said data comprises event data. Since only the stations holding the token are allowed to transmit cyclic data and event data, each station is not required to be equipped with a monitoring timer so that not only the LAN can be constructed economically but also transmission efficiency can be improved through speed up in determining the completion of data transmission.