Count Type Front End Reference Home Position Return - Mitsubishi Electric Melservo-J2-SUPER series Instruction Manual

4. OPERATION

4.4.8 Count type front end reference home position return

The position where the axis, which had started decelerating at the front end of a proximity dog, has
moved the after-proximity dog moving distance and home position shift distance is defined as a home
position. A home position return that does not depend on the Z-phase signal can be made. The home
position may change if the creep speed varies.
(1) Signals, parameters
Set the input signals and parameters as indicated below.
Item
Manual home position return mode
selection
Count type dog front end reference
home position return
Home position return direction
Dog input polarity
Home position return speed
Creep speed
Home position shift distance
Moving distance after proximity dog
Home position return acceleration/
deceleration time constants
Home position return position data
Program
(2) Timing chart
The following shows the timing chart that starts after selection of the program including the "ZRT"
command.
ON
Automatic/manual
selection (MD0)
OFF
ON
Movement complete (PED)
OFF
ON
Home position return
completion (ZP)
OFF
Forward
rotation
Servo motor speed
0 r/min
ON
Proximity dog (DOG)
OFF
ON
Forward rotation
start (ST1)
OFF
The address on completion of home position return is the value automatically set in parameter No.42
(home position return position data).
POINT
This home position return method depends on the timing of reading
Proximity dog (DOG) that has detected the front end of a proximity dog.
Hence, if a home position return is made at the creep speed of 100r/min, an
error of 200 pulses will occur in the home position. The error of the home
position is larger as the creep speed is higher.
Device/Parameter used
Automatic/manual selection (MD0) MD0 is switched on.
Parameter No.8
Parameter No.8
Parameter No.8
Parameter No.9
Parameter No.10
Parameter No.11
Parameter No.43
Parameter No.41
Parameter No.42
Select the program including the
"ZRT" command that executes a
home position return.
Home position return speed
3ms or less
5ms or more
6: Select the count type dog front end reference.
Refer to Section 4.4.1 (2) in this section and select the home
position return direction.
Refer to Section 4.4.1 (2) in this section and select the dog input
polarity.
Set the speed till the dog is detected.
Set the speed after the dog is detected.
Set when the home position is moved from where the axis has
passed the proximity dog rear end.
Set the moving distance after the axis has passed the proximity dog
rear end.
Use the acceleration/deceleration time constants set in parameter
No. 41.
Used to set the current position on completion of home position
return.
Moving distance after proximity dog
Home position shift distance
Creep speed
Proximity dog (DOG)
4 - 40
Description
Home position address
Parameter No. 42