System Selection; Maximum Movement Speed, Resolution, And Edge Distance; Important - Balluff BML-SB/C/E0-Q-M4-0-KA Serie Manual De Instrucciones

BML-S _ B/C/E0-Q _ _ _ -M4 _ _ - _ 0-KA _ _ /KA _ _-S284
Incremental Magnetic Linear Encoder
7

System selection

7.1 Maximum movement speed, resolution, and
edge distance
There is a connection between the selected resolution of
the sensor head, the minimum edge distance, and the
possible movement speed that is illustrated in Tab. 7-1 and
Tab. 7-2.
BML-S_B/S_E...: system accuracy up to 50 µm
V acc. to edge distance and resolution
max
Min. edge
distance
1)
F
5 µm
D 0.12 µs 20 m/s
E 0.29 µs 10 m/s
F 0.48 µs
5 m/s
G 1 µs
3.25 m/s
H 2 µs
1.5 m/s
K 4 µs 0.75 m/s
L 8 µs 0.375 m/s
N 16 µs 0.195 m/s 0.395 m/s
P 24 µs 0.13 m/s
1) Connection between edge distance and counting frequency, see
appendix for table.
Tab. 7-1: BML-S_B/S_E...: Selection aid for maximum movement
speed
BML-S1C...: system accuracy up to 100 µm
V acc. to edge distance and resolution
max
Min. edge
distance
1)
L M
100 µm 200 µm
M 10 µs 8 m/s 10 m/s
R 100 µs 0.9 m/s 1.8 m/s
1) Connection between edge distance and counting frequency, see
appendix for table.
Tab. 7-2: BML-S1C...: Selection aid for maximum movement speed
If using the reference sensor, the max.
movement speed is limited to 10 m/s.
16 english
Resolution
G H K
10 µm 25 µm 50 µm
20 m/s 20 m/s 20 m/s
20 m/s 20 m/s 20 m/s
10 m/s 20 m/s 20 m/s
6.5 m/s 14.75 m/s 14.75 m/s
3 m/s 7.7 m/s 7.7 m/s
1.5 m/s 3.95 m/s 3.95 m/s
0.75 m/s 1.7 m/s 1.7 m/s
0.95 m/s 0.95 m/s
0.26 m/s 0.65 m/s 0.65 m/s
Resolution
N P R
500 µm 1000 µm 2000 µm
10 m/s 10 m/s 10 m/s
4.2 m/s 8.8 m/s 10 m/s
The following applies for 4x evaluation (each edge is
counted):
Counting frequency
≥
of the controller
Period length =
Example: edge distance = 1 µs
Counting frequency = 1 MHz
Period length = 250 kHz

Important!

– The controller/display must be able to count
the minimum timed edge distances indicated
in the tables (note the counting frequency of
the controller!).
– The min. edge distance can even occur at a
standstill due to the internal interpolation
process.
– Always select the next-higher movement
speed or the next-faster min. edge distance,
otherwise position detection errors may be
created by the controller during evaluation.
Sensor head design for controlling with 4x
evaluation:
Example 1: required resolution: F = 5 µm
► In Tab. 7-1: select column 1.
Max. movement speed = 7 m/s
► Row 2 = select 10 m/s.
⇒ Edge distance E = 0.29 µs.
Example 2: required resolution G = 10 µm
► In Tab. 7-1: select column 2.
Max. counting frequency of the controller = 0.5 MHz
Edge distance H = 2 µs
► Select row 5.
⇒ Maximum possible movement speed: 3 m/s
Example 3: max. movement speed = 2 m/s
Controller detects min. edge distance M = 10 µs
► In Tab. 7-2: select row 1.
► Select column 1.
⇒ Max. possible resolution L = 100 µm (BML-S1C)
Coding in the type code breakdown
BML-S2E0-Q61_-M410-_0-KA05 (example)
Resolution
For further information, see Type code
breakdown on page 22 und 23.
1
Min. edge distance
Counting frequency
4
Min. edge distance