Mitsubishi A1SD75M1, User Manual

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12 - 60
MELSEC-A
12 CONTROL AUXILIARY FUNCTIONS
[3] Precautions during control
(1) Since the zero point data in the AD75 is initialized before shipment from the
factory, the absolute position (zero point position) cannot be restored normally.
When using the AD75 for the first time, always perform machine zero point
return control.
(2) When machine zero point return control is executed in the absolute position
detection system, access is made to the FeRAM (Ferroelectric Random
Access Memory).
The FeRAM access count is maximum 9.9999 10
9
times.
Access to the FeRAM is made three times (read is performed twice, and write
once) at power-on.
At a machine zero point return in the absolute position detection system,
(a) When the "Md.121 Absolute position restoration mode" is switched between
the "standard mode" and "infinite length mode"
Access to the FeRAM is made four times (read is performed twice, and write
twice)
(b) When the "Md.121 Absolute position restoration mode" is not switched
Access to the FeRAM is made twice (read is performed once, and write
once)
When the "
Md.120 FeRAM access count" exceeds 9.0000 10
9
times, a
warning "FeRAM count warning" (warning code: 10) occurs.
When the "
Md.120
FeRAM access count" exceeds 9.9999 10
9
times, an
error "FeRAM count over" (error code: 10) occurs. In this case, the AD75
has reached the end of its service life. Therefore, replace the module.
When the FeRAM access count exceeds 9.9999 10
9
times, the absolute
position (zero point position) cannot be restored normally at a system
startup (power on, reset, etc.).
(3) When the absolute position detection system has been configured, start
communication between the AD75 and servo amplifier after power-on or reset
to perform absolute position restoration. The parameters on the OS memory
are used for absolute position restoration. (Refer to Chapter 7 for details of the
OS memory.)
(4) When the AD75 is used in the absolute position detection system, the
followings cannot be performed.
•
Infinite length feed control* that performs control in the given direction only
•
Control in which the movement amount from the zero point address is outside
the range of Condition 1 and Condition 2 indicated below
When performing positioning in the absolute position detection system, use the
AD75 within the range that satisfies Condition 1 and Condition 2 indicated
below.
If it is used in the range that does not satisfy Condition 1 and Condition 2, a
normal current value cannot be restored at the time of absolute position
restoration and therefore the AD75 cannot be used in the absolute position
detection system.
* When the control unit is degree, set the absolute position restoration mode to
the "infinite length mode" to enable infinite length feed control. (Refer to
section 12.6.2 for details.)