Servo system

A servo system, comprising:

• a safety driver, connected to a drive device and comprising a drive signal generation circuit which generates a drive signal driving the drive device based on an action command from a standard PLC via a communication line and a feedback signal from the drive device, a drive signal path through which the drive signal is transmitted from the drive signal generation circuit to the drive device, and a safety stop circuit which cuts off the drive signal path when a stop instruction signal is input;
• a safety controller, directly connected with the safety driver by a control signal line and generating a first stop instruction signal in response to an input of an operator using an input part and outputting the first stop instruction signal to the safety stop circuit of the safety driver;
• and
• a safety communication unit, connected with the safety driver, and generating a second stop instruction signal in response to an instruction from a safety PLC via the communication line and outputting the second stop instruction signal to the safety stop circuit of the safety driver, wherein
• the safety driver has a first EDM output part which detects a cutoff of the drive signal path by the safety stop circuit and outputs an EDM signal indicating that the drive signal path is cut off,
• the safety communication unit comprises a second EDM output part which outputs the EDM signal to the safety controller in a case where the safety stop circuit is activated according to the first stop instruction signal output from the safety controller, and does not output the EDM signal to the safety controller in a case where the safety stop circuit is activated according to the second stop instruction signal.