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Absolute position detection system – MITSUBISHI ELECTRIC MR-J2S- A User Manual

Page 331

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15 - 10

15. ABSOLUTE POSITION DETECTION SYSTEM

(b) Detailed description of absolute position data transfer

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

3)

4)

5)

7)

(Note)

1)

2)

6)

Servo-on
(programmable
controller)

Servo-on
(SON)

ABS transfer mode
(ABSM)

ABS request
(ABSR)

Send data ready
(TLC)

Transmission (ABS) data

During transfer of ABS

Lower

2 bits

Checksum

Upper 2 bits

1

2

18

19

Note. If the servo-on (SON) is not turned ON within 1 second after the ABS transfer mode (ABSM) is turned ON, an SON

time-out warning (AL.EA) occurs. This warning, however, does not interrupt data transmission.
It is automatically cleared when the servo-on (SON) is turned ON.

1) The programmable controller turns ON the ABS transfer mode (ABSM) and servo-on (SON) at

the leading edge of the internal servo-on (SON).

2) In response to the ABS transfer mode (ABSM), the servo detects and calculates the absolute

position and turns ON the send data ready (TLC) to notify the programmable controller that the
servo is ready for data transmission.

3) After acknowledging that the ready to send (TLC) has been turned ON, the programmable

controller turns ABS request (ABSR) ON.

4) In response to ABS request (ABSR), the servo outputs the lower 2 bits of the ABS data and the

ready to send (TLC) in the OFF state.

5) After acknowledging that the ready to send (TLC) has been turned OFF, which implies that 2

bits of the ABS data have been transmitted, the programmable controller reads the lower 2 bits
of the ABS data and then turns OFF the ABS request (ABSR).

6) The servo turns ON the ready to send (TLC) so that it can respond to the next request.

Steps 3) to 6) are repeated until 32-bit data and the 6-bit checksum have been transmitted.

7) After receiving of the sum check, the programmable controller confirms that the 19th ABS

transmission data ready (ABST) is turned ON, and then turns OFF the ABS transfer mode
(ABSM). If the ABS transfer mode (ABSM) is turned OFF during data transmission, the ABS
transfer mode (ABSM) is interrupted and the ABS time-out warning (AL.E5) occurs.