BEI Sensors MHK5 Absolute Hollow Shaft Encoder - Manual (Page 21)

Octet 26 Bit 5 Lower limit switch
0 Deactivated
1 Activated
Octet 26 Bit 6 Upper limit switch
0 Deactivated
1 Activated
5.1.7 Physical impulses
This parameter is evaluated if the reference for the
„desired measuring units“ is „physical impulses“
(cp. 5.1.3).
With the „physical impulses“ it is possible to set a
gearing factor freely. The user defines the output
steps („desired measuring steps”) over a part of
the measuring range. This option is helpful to
program scaling factors that result in a non-integer
number of steps over 1 revolution.
Example:
Problem: The position value has to increase by
400 steps over 3 revolutions.
With the reference „steps per revolution“ it is
impossible to program that scaling factor (it would
be necessary to set the parameter „desired
measuring steps“ to 133.33; this is not possible
because the parameter must be an integer value).
Solution:
Choose „physical impulses“ as reference for the
„desired measuring units“.
Now the number of physical measuring steps over
the desired measuring range is determined. For
this the actual (physical) resolution of the encoder
(type label) is used. For our example this would be
(with a standard encoder, 12 Bit resolution):
Octet 31 32 33 34
Bit 31 - 24 23 - 16 15 – 8 7 - 0
Data 2 31 to 2 24 2 23 to 2 16 2 15 to 2 8 2 7 to 2 0
Upper limit switch (in measuring steps, related to the scaled value)
Octet 35 36 37 38
Bit 31 - 24 23 – 16 15 – 8 7 - 0
Data 2 31 to 2 24 2 23 to 2 16 2 15 to 2 8 2 7 to 2 0
Physical impulses
Revision 03/10 BEI Sensors Profibus Manual serie M Page 21