Siemens SIMATIC FM 453, Manual

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9-65
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
Table 9-11 Function Parameters – Absolute Encoders (SSI), continued
MD Comments/Unit Value/Meaning Designation
14 Number of revo-
lutions of
SSI encoder 0/1 = Single-turn encoder
2
1
...2
12
for multi-turn encoder
Only powers of 2 al-
lowed
15 SSI baud rate 2 = 156 000 Baud
3 = 312 000 Baud
4 = 625 000 Baud
5 = 1 250 000 Baud
6 = 2 500 000 Baud (no liability ac-
cepted) (Code number)
The baud rate de-
pends on the cable
length between FM
453 and encoder
19.0 Direction adjust-
ment 1 = invert measured value direc-
tion –
20
20.1
20.3
Hardware moni-
toring
1 = Error in absolute encoder
1 = Voltage monitoring
Entry for monitoring
to be switched on
MSR stands for measurement system raster (see Section 5.3.1)
Encoder: Number of increments per revolution (MD13) = 4096 = 2
12
Number of revolutions (MD14) = 256 = 2
8
Machine axis design:
S
Motor with 50:30 gear ratio on spindle with 10 mm pitch = 10,000 MSR
S
Encoder on motor.
From this one can calculate the following traversing distance per encoder
revolution:
Displacement per
encoder revolution =
50 spindle revolutions
30 motor revolutions
i 10,000 MSR = 16,666.666... MSR
Gear ratio: i = = 1.666666...
The following values are entered:
MD Value Unit
11 16 666 (10
–3
mm)
12 0.666... 2
32
= 2,863,311,530 (2
–32
10–3 mm)
13 4096 (puls/rev)
14 256 (rev)
Note
The encoder covers an absolute traversing distance of 256 16,666.666...
MSR. In the 10
–3
mm system of measurement this corresponds to a maxi-
mum axis traversing distance of 4,266.666... mm.
Sample Encoder
Adjustment
Description of Functions