Patent ID: 7222016

Claim:
A controller for a process control device with first and second sensors that generate respective feedback information indicative of operation of the process control device, the controller comprising: a first servo control module to generate a first drive signal based on the feedback information from the first sensor for control of the process control device in accordance with a first control mode; a second servo control module to generate a second drive signal based on the feedback information from the second sensor for control of the process control device in accordance with a second control mode; and a feedback control transfer module to transfer control of the operation of the process control device between the first control mode to the second control mode based on the feedback information from the first sensor, wherein the feedback control transfer module comprises a memory that maintains a record of the feedback information from the first sensor, and wherein the feedback control transfer module is capable of extracting a portion of the feedback information indicative of uncorrupted data recently received from the first sensor.