Danfoss MCO 305 Design Manual page 202

MCO 305 Design Guide
32-01 Incremental Resolution
ENCODER
Range [Unit]
1 – MLONG [PPR]
Function
The encoder resolution is used to calculate velocity
in RPM (rounds per minute) as well as timeout for
detection of the zero pulse in connection with
HOME and INDEX.
Set the resolution of the incremental encoder
connected to Encoder 2 interface (X55). Encoder
resolution can be found on encoder nameplate or
datasheet.
− Digital incremental encoder (32-00 = [1]): The
resolution must be set in Pulses per Revolution.
− Analog incremental encoder (32-00 = [2]): The
resolution must be set in sinusoidal signal
periods per revolution.
− CAN encoder (32-00 = [3]):
Incremental encoder: Pulses per revolution
Absolut encoder: (Pulses per revolution)/4
NB!:
The parameters for the incremental
resolution (32-01 or 32-31) are always
used, even if the CAN encoder is an
absolute encoder. But a quarter of the encoder
resolution must be set for a CAN absolute encoder!
The reason is the internal calculation, which uses
the four times of the number of counts, because an
incremental encoder returns 4 times more quad-
counts than its counts. An absolut encoder returns
"only" this real resolution as maximum value.
When Motor Control [3] is selected in par. 32-50
Source Slave, then the resolution can be set with
this parameter.
NB!:
When using Motor Control (SPI Encoder)
the resolution value must be a second
power, otherwise rounding errors lead to
positioning drifts (e.g. SYNCP).
Note: Maximum frequency of the encoder signal
must not exceed 410 kHz.
Note: Parameter only visible when par. 32-00 ≠ 0
default setting
202
__ Parameter Reference __
1024
[ ] value for use in communication via serial communication port
®
MG.33.L5.02 – VLT is a registered Danfoss trademark
32-02 Absolute Protocol
ENCODERABSTYPE
Option
None
Hiperface
SSI
SSI with filter
Function
Specifies type of the absolute encoder connected to
Encoder 2 interface (X55).
Select None [0] if no absolute encoder is
connected.
Select Hiperface [1] if this type of an absolute
encoder is connected. The selection includes the
default settings encoder ID "1" and encoder parity
"even".
Select SSI [4] if an absolute encoder with SSI
interface is connected.
Select SSI with filter [5] if an absolute encoder
with SSI interface is connected and the communi-
cation/signal is unstable.
A leap in the position data is detected if it is larger
than the encoder resolution/2. The correction is
made by means of an artificial position value which
is calculated from the last velocity. If the error
continues for more than 100 read-outs (> 100 ms),
there will be no further correction which will then
indeed lead to a "position error" (error 108).
The total number of errors will be saved in an
internal variable which can be read out via
SYSVAR[16].
NB!:
The following commands cannot be used
with absolute encoders: DEFORIGIN,
HOME, INDEX, IPOS, and WAITNDX.
Note: Selection [1] Hiperface encoder is available
with version 6.7.40.
32-03 Absolute Resolution
ENCODERABSRES
Range
1 ... MLONG
Function
The encoder resolution is used to calculate velocity
in RPM (rounds per minute).
[0]
[1]
[4]
[5]
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