Mitsubishi Electric MELSEC iQ-F FX5 Programming Manual page 884

• The following figure shows the operation at completion of the G.ABRST instruction.
Sequence scan
G.ABRST instruction
Completion device(d)
Completion status
indication device (d1)+1
• Completion of absolute position restoration can be checked with the (s)+4 status.
• The G.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 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 G.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.
• For details of the function, refer to MELSEC iQ-F FX5 User's Manual (Positioning Control - Intelligent function module).
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.
• Absolute position restoration must be performed while the [Cd.190] PLC READY signal is off. While [Cd.190] PLC READY
signal is ON, if the G.ABRST instruction is executed, "Dedicated instruction error (Error code: 1870H)" occurs in the
positioning module and absolute position restoration cannot be executed.
• The absolute position can be restored (the G.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) for the period of the scan time
plus approximately 60 ms and the motor may move. 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 G.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 (GP.PSTRT)
• Absolute position restoration instruction (G.ABRST)
• Teaching instruction (GP.TEACH)
• If this instruction is executed in an interrupt program with the priority 1, operation error (3580H) occurs. This instruction
operates in an interrupt program with the priority 2 or 3.
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.
16 POSITIONING INSTRUCTION
882
16.2 Positioning Module
0 END 0
Instruction execution
OFF
OFF
END 0 END 0
Instruction execution complete
ON
ON
END 0
OFF
When completed with an error
OFF
When completed
normally
1 scan
END