A motor controller (20, 30) connected to a network, the motor controller (20, 30) comprising: a communication circuit configured to transmit and receive a signal through the network; a motor control unit configured to output a motor drive command value for driving a motor (90, 100) in accordance with a command value received through the communication circuit; a motor drive circuit configured to output a motor voltage command signal for driving the motor (90, 100) in accordance with the motor drive command value; an inverter configured to supply power for driving the motor (90, 100) by switching based on the motor voltage command signal; a safety control unit configured to output a drive permission signal for driving the motor (90, 100) in accordance with communication data received through the communication circuit; a cut-off circuit configured to receive the drive permission signal and the motor voltage command signal, and cut off the motor voltage command signal to the inverter when receiving no drive permission signal; and a safety input unit configured to receive a redundant safety input signal, wherein the cut-off circuit is configured to receive a logical AND of the safety input signal and the drive permission signal, and wherein the motor controller (20, 30) outputs no motor drive command value when the cut-off circuit is cutting off the motor voltage command signal, wherein the safety control unit further includes a safety communication unit configured to process safety data included in the communication data in accordance with a predetermined protocol, and a safety processing unit configured to output no drive permission signal when the safety data that has been processed by the safety communication unit includes a signal for placing the motor (90, 100) into a safe status and when the safety processing unit receives a notification about a communication abnormality from the safety communication unit. a communication circuit configured to transmit and receive a signal through the network; a motor control unit configured to output a motor drive command value for driving a motor (90, 100) in accordance with a command value received through the communication circuit; a motor drive circuit configured to output a motor voltage command signal for driving the motor (90, 100) in accordance with the motor drive command value; an inverter configured to supply power for driving the motor (90, 100) by switching based on the motor voltage command signal; a safety control unit configured to output a drive permission signal for driving the motor (90, 100) in accordance with communication data received through the communication circuit; a cut-off circuit configured to receive the drive permission signal and the motor voltage command signal, and cut off the motor voltage command signal to the inverter when receiving no drive permission signal; and a safety input unit configured to receive a redundant safety input signal, wherein the cut-off circuit is configured to receive a logical AND of the safety input signal and the drive permission signal, and wherein the motor controller (20, 30) outputs no motor drive command value when the cut-off circuit is cutting off the motor voltage command signal, wherein the safety control unit further includes a safety communication unit configured to process safety data included in the communication data in accordance with a predetermined protocol, and a safety processing unit configured to output no drive permission signal when the safety data that has been processed by the safety communication unit includes a signal for placing the motor (90, 100) into a safe status and when the safety processing unit receives a notification about a communication abnormality from the safety communication unit.