Siemens SINUMERIK 840Di Function Manual page 386

Detailed Description
2.2 Metric/inch measuring system
2.2.2 Conversion of basic system by parts program
Conversion factor
The factor for inch/metric conversion for data input and output can be changed via machine
data element:
MD10250 $MN_SCALING_VALUE_INCH (conversion factor for changing to the inch
system).
Note
The machine data element is not visible unless the password of protection level "Siemens" is
set.
By changing the default value, the control can be adapted to a customer-specific measuring
system.
When programming, it is possible to change over between measuring systems for some
workpiece-related specifications with G70/G71/G700/G710. The data that can be influenced
by G70/G71/G700/G710 is described in the Programming Guide.
The initial state of G70/G71/G700/G710 can be defined channel-specifically via the G group
initial state (reset) in machine data:
MD20150 $MC_GCODE_RESET_VALUES[12].
When changing the measuring system via the relevant soft key on the HMI, these initial
settings are automatically predefined to appropriate settings for the new measuring system
with G700 or G710.
The axis-specific machine data element:
MD31200 $MA_SCALING_FACTOR_G70_G71
(factor for converting values with active G70/G71/G700/G710)
can be used to freely select the conversion factor between metric and inch conversion with
G70/G71/G700/G710 programming.
The controller can be adapted to a customized measuring system by changing the
predefined settings. The factor only takes effect if parts program programming differs from
the initial state.
Example:
Initial state: inch; (MD10240 $MN_SCALING_SYSTEM_IS_METRIC=0)
Parts program:
N15 G70
N20 G71
2-12
; Factor is not effective, since the setting is exactly the
same as the initial state.
; Factor is effective.
Velocities, Setpoint/Actual-Value Systems, Closed-Loop Control (G2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0