Instruction Manual

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
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 automaticall
y
cleared when the servo-on
(
SON
)
is turned ON.
During transfer of ABS
Lower
2 bits
Check sum
Upper 2 bits
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 check sum have been transmitted.
7) After receiving of the check sum, the programmable controller turns the ABS transfer mode
(ABSM) OFF.
If the ABS transfer mode (ABSM) is turned OFF during data transmission, the ABS transfer
mode (ABSM) is interrupted.