Etel DSC Series User Manual

Operation & Software Manual
144
Direct Drives & Systems
Chapter C: System functions ETEL Doc. - Operation & Software Manual # DSC2P 903 / Ver. F / 3/6/05
13.2.1.1 External reference setting:
Parameters K222 to K224 ’set up’ the external reference.
The external reference formula taken from the 'unset' external reference (value of the register given by
parameters K220 and K221) is:
Parameter K222 makes the first ’gross’ multiplication from the unset external reference. This multiplication
is useful when a voltage on an analog input is used as reference because the analog input possesses an A/D
converter which can convert a voltage between +10V and –10V into a value between -32767 to +32767. For
instance 32767 is a very low value for a position reference that can easily reach millions of increments. This
value must be multiplied by a very high number if a movement of more than a few millimeters is wished.
After that first multiplication, the value contained in parameter K223 is subtracted to the external reference. This
offset moves the origin according to the user’s needs.
It is then multiplied by . It tunes the reference amplitude. Unlike the first operation which only increases
the amplitude signal, it can decrease it (K224<2
24
) and invert the reference sign (K224<0).
The following diagram shows the different steps. They are the same for all external reference modes. In the
following example, a signal sent to the analog input has been chosen for the external reference.
Remark: Refer to §20.
for more information about the units of the external reference
Each external reference will now be reviewed in the next paragraphs.
external ref. set 'unset' external ref. not set
( 2
K222
K223 )
K224
2
24
-------------
⋅–⋅=
K224
2
24
-------------
External
reference
not set
External
reference
set
’Gross’
multiplication
Offset
correction
Amplitude
correction
ext. ref. U[V]
ext. ref.
ext. ref.
ext. ref.
ext. ref.
Analog external reference
A
D
10[V]
-10[V]
32767
-32768
K222 K223
K224
32767
-32768
32767
-32768

Etel DSC Series Specifications

General

Brand	Etel
Model	DSC Series
Category	Controller
Language	English