Siemens SIMATIC FM 453, Manual

Page: 256 / 380

9-56
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
9.4 System of Measurement
At the start of parameterization, you must fill in the basic machine data item
system of measurement (MD7). This item governs the input of values.
You can set the system of measurement for the following three units:
S
mm
S
inches
S
degrees
All value inputs and all value ranges refer to the setting in the system of mea-
surement.
In “Parameterize FM 453” and in the FM 453 itself, values are processed in
the following base units:
S
0,001
mm
S
0.0001 inch
S
0.0001 degree
The sample values in the table below illustrate the relation between the sys-
tem of measurement and internal values:
System of
Measurement
Internal Values Input at Interface
mm 10
-3
mm 10 995
@
10
-3
mm 10.995 mm
inches 10
-4
inch 10 995
@
10
-4
in(ch) 1.0995 inch
degrees 10
-4
degree
10
-2
degree
3,600,000
@
10
-4
de-
gree
36,000
@
10
-2
degree
360.0000 degree
360.00 degree
Note
The measurement system (MD7) must match the measurement system speci-
fied in the other DBs.
The measurement system raster (MSR) is the smallest distance unit in the
active system of measurement.
If at some point you have failed to take this precaution:
1. Delete all data blocks of the relevant channel (which do not match the
measurement system) or clear the memory of the FM 453 completely.
2. Modify the other data blocks on the programming device.
3. Reload the data blocks to the FM 453.
Overview
Variants of the
System of
Measurement
Input of
Machine Data
Internal
Processing
of Values
Examples
Description of Functions