Mitsubishi A1SD75M3

12 - 66
MELSEC-A
12 CONTROL AUXILIARY FUNCTIONS
[2] Control details
The operation performed for absolute position restoration mode switching is described
below.
1) To switch the absolute position restoration mode, select the mode in
"
Pr.59
Absolute position restoration selection" and make a machine
zero point return.
The absolute position restoration mode is established when the zero
point return complete flag (
Md.40
Status: b4) turns ON.
2) When power is switched from OFF to ON after execution of Step 1),
the system starts up in the mode established in Step 1) and restores
the absolute position.
The established absolute position restoration mode can be checked in the "
Md.121
Absolute position restoration mode".
When the "
Md.121
Absolute position restoration mode" is "1: Infinite length mode", the
AD75 automatically updates the absolute position of the zero point stored in the
FeRAM every time the machine moves the given distance* (servomotor shaft: 8142 to
8192 revolutions). This detects the absolute position for infinite length positioning
control. Every time the absolute position is automatically updated, the "
Md.120
FeRAM
access count" is incremented by "2".
* The given distance is automatically determined by the setting of "
Pr.2
No. of
pulses per rotation".
Md.40
Zero point return complete flag
Status: b4
Machine zero point return start
(Positioning start signal) [Y10,Y11,Y12]
OFF
ON
OFF
OFF
ON
Standing by
In zero point return
Zero point return request flag
Status: b3Md.40
Standard mode
OFF
ON
Standard mode Infinite length mode
AD75 READY signal [X0]
PLC READY signal [Y1D]
ON
OFF
ON
Infinite length mode
Pr.59
Absolute position
restoration selection
Axis operation status
Md.35
Absolute position restoration
mode
Md.121
Standing by
Fig. 12.34 Absolute position restoration mode switching operation