PROFIBUS USER MANUAL Leine & Linde AB
Part Id: 740590-01
23
Document Id: 740590 Ver. 01
Publication date: 2010-06-01
5.4.5 Measuring units per revolution
The total measuring range is calculated by multiplying the singleturn resolution with
the number of distinguishable revolutions.
The default settings for multiturn encoders RXA 607 are:
Measuring units per revolution= 8192
10
(2
13
)
Total measuring range in measuring units= 8192
10
(2
13
x 2
0
)
The default settings for multiturn encoders RXA 608 are:
Measuring units per revolution= 8192
10
(2
13
)
Total measuring range in measuring units= 33554432
10
(2
13
x 2
12
)
Format of the scaling parameters:
Octet:
10
11
12
13
Bits
31 – 24
23 – 16
15 – 8
7 – 0
Data
231 – 224
223 – 216
215 – 28
27 –20
Measuring units per revolution
Table 13 Singleturn scaling parameter format
Octet:
14
15
16
17
Bits
31 – 24
23 – 16
15 – 8
7 – 0
Data
231 – 224
223 – 216
215 – 28
27 –20
Total measuring range in measuring units
Table 14 Multiturn scaling parameter format
The data format for both scaling parameters is 32 bits without sign, with a value
range from 2
0
to 2
31
. The permissible value range is limited by the resolution of the
encoder. For a 25-bit encoder with a singleturn resolution of 13 bits the permissible
value range for "Measuring units per revolution" is between 2
0
and 2
13
(8192) and for
the "Total measuring range in measuring steps" the permissible value range is
between 2
0
and 2
25
(33 554 432). The scaling parameters are securely stored in the
PROFIBUS-DP master and are reloaded into the encoder at each power-up. Both
parameters are output data in 32-bit format.
Example of scaling and entry:
If the user wants to scale the encoder to a single turn resolution of 4000 unique
positions per revolution and a total number of turn count equal to 3200 revolutions
shall the configuration be as:
Measuring units per revolution
=
4000
10
steps
Total measuring range in measuring units
= 4000 steps x 3200 revolutions
= 12 800 000
10
Entry in the master configuration software:
Measuring units per revolution
= 4000
Total measuring range (steps)
= 12800000