Hardware Requirements; Accuracy - Siemens SINUMERIK 840C Installation Instructions Manual

12 Functional Descriptions
12.11.2 ENDAT absolute encoder (SW 5.2 and higher)
12.11.2.2
The ENDAT absolute encoder can only be used in conjunction with the new digital
SIMODRIVE 611D modules "Standard and performance".
Order No.: 6SN1118-0DM13-0AA0 2-axis version (Standard)
Order No.: 6SN1118-0DG23-0AA0 1-axis version (Performance)
Order No.: 6SN1118-0DH23-0AA0 2-axis version (Performance)
The necessary software is available as from NC software version 5.2.
12.11.2.3
Relevant measuring system data
• Grid spacing:
The size of the grid spacing (=size of the pitch period of the finest track) is taken from the
company data sheet for the EnDat encoder.
• EnDat measuring step:
The EnDat measuring step (effectively the same as the EnDat encoder resolution) is taken
from the company data sheet for the EnDat encoder.
• Incremental measuring step:
The incremental measuring step (= measuring system resolution with which the NC
position control is working) results from the interaction between incremental encoder and
interpolating evaluation electronics (HW + SW).
Incremental measuring step = grid spacing/product of all pulse multiplications).
• NC-MD 1264* (grid spacing/EnDat measuring step):
The NC requires this MD to convert the EnDat measuring steps into incremental
measuring steps. Only input values which are integer and can be divided by 4 are
processed by the control. With this MD, the default value = 0 for the encoder EQN 1325
is correct, i.e. it is internally interpreted as value 4. In the list display: User displays/NC
data/Axis/Measuring system data, this MD is entered directly after MD 1808*, bit 6.
Example
Spindle pitch
No. of encoder markings, finest track
Internal pulse multiplication
External pulse multiplication (interpolation)
Position controller resolution
Rotary grid spacing=
Linear grid spacing=
12–82
More user manuals on

Hardware requirements

Accuracy

EQN 1325:
1 revolution
2048
10 mm
2048
ManualsBase.com
10 mm
2048
4
512
-3 mm, (0.5 µm)
0.5 *10
= 0.000488 rev.
µ
= 4.88 m
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SINUMERIK 840C (IA)