Lika POWERLINK EM58 PL, Руководство пользователя

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EM58 • HS58 • HM58 POWERLINK
6003 Preset value
[Unsigned32, rw]
This object allows to set the encoder position to a Preset value. The Preset
function is meant to assign a desired value to a physical position of the encoder
shaft. The chosen position will get the value set next to this object and all the
previous and the following positions will get a value according to it. This
function is useful, for example, when the zero position of the encoder and the
zero position of the axis need to match. The preset value will be set for the
position of the encoder in the moment when the preset value is transmitted. We
suggest setting the preset value when the encoder is in stop.
To execute the preset you must transmit the value to the
6003 Preset value
object in the asynchronous phase via SDO when the encoder is in operational
state (
NMT_CS_OPERATIONAL
) and then execute the
Store parameters
function (see the
Store parameters
function on page 92).
Default = 0 (min. = 0, max. = 134217727 *) for EM58 series
0 (min. = 0, max. = 262143 *) for HS58 series
0 (min. = 0, max. = 1073741823 *) for HM58 series
* See the NOTE below.
EXAMPLE
Let's take a look at the following example to better understand the preset
function and the meaning and use of the related objects:
6003 Preset value
and
6509 Offset value
.
The encoder position which is transmitted results from the following
calculation:
Transmitted value
=
read position
(it does not matter whether the position is
physical or scaled) +
6003 Preset value
-
6509 Offset value
.
If you never set the
6003 Preset value
and you never performed the preset
setting, then the transmitted value and the read position are necessarily the
same as
6003 Preset value
= 0 and
6509 Offset value
= 0.
When you set the
6003 Preset value
and then execute the preset setting, the
system saves the current encoder position in the
6509 Offset value
object. It
follows that the transmitted value and the
6003 Preset value
are the same as
read position
-
6509 Offset value
= 0; in other words, the value set next to
the
6003 Preset value
object is paired with the current position of the encoder
as you wish.
For example, let's assume that the value “50” is set next to the
6003 Preset
value
object and you execute the preset setting when the encoder position is
“1000”. In other words, you want to receive the value “50” when the encoder
reaches the position “1000”.
We will obtain the following information sequence:
Transmitted value
=
read position
(=”1000”) +
6003 Preset value
(=”50”) -
6509 Offset value
(=”1000”) = 50.
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