Restoration Of The Actual Position - Siemens SINUMERIK 840D Function Manual

R1: Referencing
10.10 Automatic restoration of the machine reference
Boundary conditions
Encoder activation with MD34210 $MA_ENC_REFP_STATE[<encoder>] == 1
An encoder state equal to "1" at the time of the encoder activation means that "Automatic
referencing" has been enabled. However, the measuring system has either not been
referenced yet or the machine axis was not switched off at standstill in the "Exact stop fine"
state. The following is set for the machine axis or the active measuring system:
● Actual position = 0
● Active measuring system, encoder state = "Not referenced":
DB31, ... DBX60.4 / .5 = 0 (referenced/synchronized 1/2)
Further information
Referencing with incremental measurement systems (Page 296)
10.10.3

Restoration of the actual position

Function
When restoring the actual position to the last buffered position, the encoder state of the active
measuring system is set to "Restored". The axis can only be traversed manually.
AUTOMATIC mode
To enable NC start for the automatic execution of programs in the AUTOMATIC mode, the
measuring system of the machine axis must be re-referenced.
MDI mode and overstore
In the MDI mode and for the overstore function, machining can also be performed, without
referencing the axes, with restored positions. To do this, NC start with restored positions must
be enabled explicitly for a specific channel:
MD20700 $MC_REFP_NC_START_LOCK = 2
Requirement
The measuring system that is active when the control is switched on must already have been
referenced once before switching off.
Parameterization
Release: Restoration of the actual position
The enable to restore the actual position is performed by setting the encoder state to "The last
buffered axis position before switching off will be restored, no automatic referencing":
MD34210 $MA_ENC_REFP_STATE[<encoder>] = 3
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Axes and spindles
Function Manual, 06/2019, A5E47437747B AA