Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1770

• The following figure shows the operation at completion of the ABRST instruction.
Sequence scan
ABRST instruction
Completion device (d)
Completion status
indication device (d)+1
• Completion of absolute position restoration can be checked with the (s)+4 status.
• The ABRST instruction performs absolute position restoration by following procedure.
1.
Output data from ((s)+3).
Servo on, ABS transfer mode, and ABS request flag are output to the output module by using the program.
2.
Set data in ((s)+2).
ABS data bit 0/bit 1 and the send data ready flag are set using the program.
3.
Execute the ABRST instruction.
4.
Check whether the value in ((s)+4) is 0 or not.
When the value is other than 0, the processing returns to step 1.
When the value is 0, the processing ends.
Precautions
• If the absolute position detection system has been constructed, absolute position restoration must be performed once after
the power is turned on or reset. The servo does not turn on until the absolute position restoration completes with the
positioning module.
• Absolute position restoration must be performed while the programmable controller ready signal [Y0] is off.
• The absolute position can be restored (the ABRST instruction can be executed) while a servo amplifier is operable. Note
that when the absolute position is restored, the Servo on signal may turn off (servo off) during the period of the scan time
plus approximately 60ms and the module may operate. To restore the absolute position during the servo off state, install an
electromagnetic brake separately so that signals are output to the electromagnetic brake while the ABRST instruction is
being executed.
• The following instructions cannot be executed simultaneously to a single axis. For different axes, any of the following can
be executed concurrently with a G.ABRST instruction.
• Positioning start instruction (PSTRT)
• Absolute position restoration instruction (ABRST)
• Teaching instruction (TEACH)
Operation error
Error code Description
((s)+1)
1860H A value other than 0 was set in "Status" of (s)+4 (at start of communication with the servo amplifier).
1861H "Status" of (s)+4 was changed during absolute position restoration (i.e. during communication with the servo amplifier).
1865H An instruction was specified for an undefined axis (e.g. the G.ABRST3 instruction was specified when RD75P2 is used).
22 POSITIONING INSTRUCTIONS
1768
22.1 Restoring the Absolute Position
0 END 0
Execution of
the instruction
OFF
OFF
END 0 END
ON
ON
0 END 0
Completion of the instruction
OFF
Completed with an error
OFF
Completed successfully
1 scan
END