12.93
The parameters for defining MD 455* and 456* can be taken from the table below.
Parameter
Position control resolution
Pulses per resolution
Pulse multiplication
Measuring gear
Parameters for defining MD 455* and 456*
MD 455* = 4
MD 456* =
If the values thus calculated are greater than the input limits, common factors must be
reduced.
Recommendation: Always reduce when possible, at least for values 100 000
Notes
•
The position control resolution has been set to 0.5 x 10
•
If the spindle is allocated to a C axis (MD 461*), the C axis resolution is used for the
calculations (MD 1800*, 364*, 368*).
•
The default values apply to the use of an SPC servo loop module and an encoder with
1024 pulses per revolution (see Example).
Examples
•
Encoder mounted directly on the spindle; square pulse encoder and SPC servo loop
module
b
p
f
r1 =
r2 =
If the spindle performs one full revolution, the encoder generates 4 x 1024=4096 pulses.
If these factors are introduced into the formula:
MD 4550 =
MD 4560 =
Reduction by the common factor 128 yields:
MD 4550 =
MD 4560 =
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Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
More user manuals on
p
f
r2
Number of measuring system pulses per encoder revolution
•
•
•
including hardware multiplication; multiplied by r2
360
r1
Number of internally computed increments per encoder revolution;
•
multiplied by r1
b
-3
=
0.5
10
degrees
•
=
1024
pulses per revolution
=
1
no pulse multiplication
1
no measuring gear
1
4 096
720 000
32
5625
ManualsBase.com
6 NC Machine Data (NC MD), NC Setting Data (NC SD)
Symbol
Meaning
b
Reference unit for traversing path
p
Number of encoder pulses per
resolution
f
Pulse multiplication for HMS
measuring circuit module; MD 458*
r1 / r2
Gear transmission ratio between
spindle and encoder
-3
degrees for the spindle.
6FC5197- AA50
6.5 Spindle-specific MD (spindle data)
6–73