Wachendorff WDGA CANopen, Technical Manual, Page: 76 / 82

Technical Manual
WDGA with CANopen-Interface
8 - Setting-up the encoder
© Wachendorff Automation GmbH & Co. KG 65 Rev.1.24
You don’t have to use PDOs to check the current position value. You can also perform
a SDO read access on the position value object 6004h:
600h+ID 8 40h 04h 60h 00h 00h 00h 00h 00h
CAN-ID DLC Command Object
L
Object
H Sub-
Index Byte0 Byte1 Byte2 Byte3
Table 8.66: Check current position
The encoder will respond with the current position value.
8.8 Position value filtering
The encoder provides an internal filtering for the position value. Sub-index 1 of object
2105h is the filter parameter for the internal " IIF"-filter (infinite impulse response filter).
01h for the filter parameter deactivates the filter. The maximum value is 04h. A filtered
position value is more stable at the cost of less dynamic.
8.9 Change speed-integration and speed scaling
The encoder uses an " integration time " to calculate the speed value. This time interval
can be adjusted by object 2105h, sub-Index 2. The unit for this time is milliseconds.
The default value of 1000 milliseconds is suitable for most applications.
The change of the integration time will result in a more or less dynamic behaviour of
the speed value, similar (but independent) to the filtering of the position value.
The speed scaling can be edited by object 2106h. The Sub-Indices 1 (= numerator)
and 2 (= denominator) form a scaling factor (here: "z") for the speed scaling. Default
value is "1". The speed value is always given in
Increments per second .
Object 2106h is a signed16 value with the limits of ±32767 representing ±120 rotations
per second.
For example the speed shall be scaled to a maximum of ±2500 rpm:
𝑧 = Skaling factor ⇒ 𝑧 =
𝑘
𝑛
(1)
𝑛 = Max rotation per sec ⇒ 𝑧 =
120
2500
(2)
𝑘 = Calculation factor = 120 ⇒ 𝑧 =
6
125
(3)
So object 2106h-01h must be set to 6d = 06h and 2106h-01h set to 125d=7Dh, so the
limits of ±32767 are scaled to ±2500 U/min.
Applying this scaling, the limits ±32767 corresponds with ±2500 rpm.