Servomotor drive device

A servomotor drive device comprising:

• an encoder configured to detect rotation of a servomotor that is a driving source for a driving target object;
• a servo amplifier configured to perform feedback control of the rotation of the servomotor based on an encoder value of the encoder;
• and
• an amp control section configured to control operation of the servo amplifier, wherein
• the amp control section is configured to:
• determine whether or not an error has occurred with the encoder;
• when it is determined that the error has not occurred with the encoder:
• calculate a command value for controlling the servomotor;
• and
• when it is determined that the error has occurred with the encoder:
• instead of calculating the command value, send an initialization instruction for initializing the encoder to the servo amplifier in a state of fixed cycle connection over a servo network between the servo amplifier and the encoder, and
• the servo amplifier is configured to:
• perform initialization of the encoder without disconnecting the servo network when receiving the initialization instruction sent from the amp control section.