A device for a robot is disclosed. In the device for a robot, a first signal is transmitted from a robot control device to the robot, a second signal is transmitted from the robot control device to the device for a robot, and a third signal is transmitted from the robot control device to the device for a robot, the third signal being transmitted from the robot control device in a case where there is a communication error between the robot control device and the device for a robot so that the device for a robot is restarted via a reset circuit.

The described methods and systems enable process control devices to transmit and receive device variable values in a manner that enables the receiving device to verify the integrity of the received values on a variable-by-variable basis. To facilitate verification of integrity, any desired number of variables in a message may have a data integrity check in the message. For each received value that has a data integrity check, the receiving device can calculate its own data integrity check based on the received value and a seed (known to both the transmitting and receiving devices), which it can then compare to the received data integrity check to verify if the received value has been altered during communication.

The described methods and systems enable process control devices to transmit and receive device variable values in a manner that enables the receiving device to verify the integrity of the received values on a variable-by-variable basis. To facilitate verification of integrity, any desired number of variables in a message may have a data integrity check in the message. For each received value that has a data integrity check, the receiving device can calculate its own data integrity check based on the received value and a seed (known to both the transmitting and receiving devices), which it can then compare to the received data integrity check to verify if the received value has been altered during communication.

It is desired to be able to easily identify a cause of a communication abnormality in an industrial machine. A controller of an industrial machine which communicates with an external device through a network includes: a plurality of communication units which respectively correspond to a plurality of communication protocols; and a diagnosis unit which starts up the communication units in a predetermined order and attempts communication using the communication protocols corresponding to each communication unit that is started up so as to diagnose the conditions of communication step by step.

A machine tool includes three mutually independent data transmission mechanisms. The data transmission mechanisms include respective transmission units which assign codes for detecting errors to data acquired from the output of sensors, and which transmit the data. A machine controller includes an operation judgment unit which judges whether operation of a feed axis motor is continued. The operation judgment unit judges that operation is continued when there are two pieces of data for which a relationship between the data and the code matches a rule, and the two pieces of data are within a predetermined judgment range. The operation judgment unit judges that the feed axis motor is stopped when at least one of the pieces of data for which the relationship matches the rule deviates from the judgment range.

It is desired to be able to easily identify a cause of a communication abnormality in an industrial machine. A controller of an industrial machine which communicates with an external device through a network includes: a plurality of communication units which respectively correspond to a plurality of communication protocols; and a diagnosis unit which starts up the communication units in a predetermined order and attempts communication using the communication protocols corresponding to each communication unit that is started up so as to diagnose the conditions of communication step by step.

A device for a robot is disclosed. In the device for a robot, a first signal is transmitted from a robot control device to the robot, a second signal is transmitted from the robot control device to the device for a robot, and a third signal is transmitted from the robot control device to the device for a robot, the third signal being transmitted from the robot control device in a case where there is a communication error between the robot control device and the device for a robot so that the device for a robot is restarted via a reset circuit.