Siemens SINUMERIK 802D sl Function Manual page 121

If the switchover cannot be performed, this is indicated by a message in the user interface.
These measures ensure that a consistent set of data is always used for a running program
with reference to the system of measurement.
The actual switchover of the system of measurement is performed internally by writing all the
necessary machine data and subsequently activating them with a Reset.
MD10240 SCALING_SYSTEM_IS_METRIC and the corresponding G70/G71/G700/G710
settings in MD20150 GCODE_RESET_VALUES are switched over automatically and
consistently. The value of machine data: MD20150 GCODE_RESET_VALUES[12] (initial
setting of the G groups) varies between G700 and G710.
This process takes place independently of the protection level currently set.
Note
MD20150 can only be read/written in expert mode (protection level 1).
System data
When changing over the measuring system, from the view of the user, all length-related
specifications are converted to the new measuring system automatically. This includes:
● Positions
● Feed rates
● Acceleration rates
● Jerk
● Tool offsets
● Compensation values
● Machine data
● Jog and hand wheel factors
After the changeover, all of the above data is available in the physical quantities described in
Section "Standardizing physical quantities of machine and setting data".
Data, for which no unique physical units are defined, such as R parameters, is not converted
automatically. The user is prompted to take the current valid measuring system MD10240
SCALING_SYSTEM_IS_METRIC into consideration.
The current dimension system setting can be read at the PLC interface via the "inch system"
signal (V2700 0001.7).
Reference point
The reference point is retained. It is not necessary to repeat referencing.
Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0
Velocities, Setpoint/Actual Value Systems, Closed-Loop Control (G2)
7.2 Metric/inch measuring system
121