Encoder, controller, method for processing data

1. An encoder comprising:

a first disc and a second disc mounted on a rotation shaft of a motor;

a first detector configured to detect a rotation position of the first disc within one rotation of the first disc;

a second detector configured to detect that the second disc has made one rotation;

a rotation count detector configured to count a rotation count of the second disc based on an output from the second detector;

a sender configured to send sending data comprising the rotation position and the rotation count;

a first error detection sign adder configured to add a first error detection sign to the rotation count; and

a second error detection sign adder configured to add a second error detection sign to the sending data.

2. The encoder according to claim 1 ,

wherein the first error detection sign adder is configured to add a first CRC value to the rotation count, and

wherein the second error detection sign adder is configured to add a second CRC value to the sending data.

3. The encoder according to claim 2 ,

wherein the first disc comprises an optical disc, and

wherein the second disc comprises a magnetic disc.

4. The encoder according to claim 2 , further comprising a test counter generator configured to generate a test counter that indicates a different value every time the sending data is sent,

wherein the first error detection sign adder is configured to add the first error detection sign to the rotation count and the test counter.

5. The encoder according to claim 4 ,

wherein the first disc comprises an optical disc, and

wherein the second disc comprises a magnetic disc.

6. The encoder according to claim 1 ,

wherein the first disc comprises an optical disc, and

wherein the second disc comprises a magnetic disc.

7. A controller comprising:

a receiver configured to receive sending data from an encoder of a motor, the sending data comprising: a rotation position of a rotation shaft of the motor within one rotation of the rotation shaft; and a first rotation count of the rotation shaft;

a first rotation count obtainer configured to obtain a second rotation count of the rotation shaft based on a change in the rotation position of the rotation shaft within the one rotation of the rotation shaft;

a second rotation count obtainer configured to obtain the first rotation count included in the sending data;

a comparer configured to compare the second rotation count obtained by the first rotation count obtainer with the first rotation count obtained by the second rotation count obtainer;

a first error detector configured to check a first error detection sign added to the rotation count included in the sending data; and

a second error detector configured to check a second error detection sign added to the sending data.

8. The controller according to claim 7 , further comprising a test counter determiner configured to determine whether a value indicated by a test counter included in the sending data is correct.

9. The controller according to claim 7 ,

wherein the first error detector is configured to check a first CRC value added to the rotation count included in the sending data, and

wherein the second error detector is configured to check a second CRC value added to the sending data.

10. The controller according to claim 9 , further comprising a test counter determiner configured to determine whether a value indicated by a test counter included in the sending data is correct.

11. A method for processing data, the method comprising:

detecting, using a first sensor, a rotation position of a first disc within one rotation of the first disc, the first disc being mounted on a rotation shaft of a motor;

detecting, using a second sensor, that a second disc mounted on the rotation shaft has made one rotation;

counting a rotation count of the second disc based on an output from the second detector;

sending data comprising the rotation position and the rotation count;

adding, using a first error detection sign adder, a first error detection sign to the rotation count; and

adding, using a second error detection sign adder, a second error detection sign to the sending data.