Controlled tape stopping with feed forward during power loss

In a tape data storage system having a motor driven tape supply reel and a motor driven tape take-up reel and a tape path therebetween for retrieving data from or storing data to the tape, a method for maintaining integrity of the tape path comprising the steps of:

• driving the supply reel motor and the take-up reel motor in a forward direction from a power supply during normal data storage and retrieval operations;
• in response to failure of said power supply, applying dynamic braking to said supply reel motor and the take-up reel motor;
• sensing the relative momentum of said supply reel and take-up reel during said applying step;
• and
• applying an alternative supply of driving current to said take-up reel in response to detection of a significantly greater momentum of said supply reel in said sensing step;
• wherein destructive loosening of said tape path during the power supply failure condition is avoided.

A reel to reel tape drive system for storing and accessing digital data, said system comprising:

• first and second drive motors coupled to respective supply and take-up reels;
• a motor control processor, connected to a power supply source and to each of said first and second drive motors;
• a backup power supply;
• a plurality of reel condition sensors;
• and
• a power loss sensor;
• wherein
• current from the backup power supply is supplied to drive the take-up reel motor while braking current is supplied to the supply reel motor upon loss of said power supply source and in response to a sensed imbalance condition by said reel condition sensors.