7 physical measuring steps, 8 encoder type – ifm electronic RN3001 User Manual
Page 18
Encoder with Profibus interface
18
10.1.7 Physical measuring steps
Octet
35
36
37
38
Bit
31���24
23���16
15���8
7���0
Data
2
31
���2
24
2
23
���2
16
2
15
���2
8
2
7
���2
0
Physical measuring steps
This parameter is evaluated by the device if the option [Physical impulses] was
selected as reference to the requested measuring steps� By means of the physical
measuring steps a gearbox factor can be freely set� Here it is defined how many
measuring steps (requested measuring steps) are to be provided on a defined
sub-measuring range� This option is useful if "odd" scaling factors are to be
entered�
Example
The encoder is to provide 400 steps over 3 revolutions�
With the reference [Desired measuring units per revolution] this number of steps
cannot be set (the [Desired measuring units] parameter should contain the value
133�333; however only integers can be entered)�
Remedy
The physical measuring steps are selected as reference for the requested
measuring steps�
The number of the physical measuring steps over the requested measuring range
is determined on the basis of the actual (physical) resolution of the device (type
label)� For this absolute encoder with 12-bit standard resolution this would in this
case be
4096 steps/revolution x 3 revolutions = 12288 steps
This value is now entered as [Physical impulses] parameter; the actually required
number of steps of 400 is entered at [Desired measuring units]� The encoder
now provides 400 steps over a measuring range of 12288 physical steps (i�e� 3
revolutions)�
Note: With many projection tools it may be required to split the value into high
word and low word�
10.1.8 Encoder type
The type of encoder (singleturn or multiturn) is defined in bit 1 of octet 39� This
is done automatically when the encoder class is selected� The user only has to
consider this parameter if parameters are set directly in the hexadecimal code�
Octet 39 bit 1
Type
0
Singleturn
1
Multiturn