Etel DSC Series User Manual

Operation & Software Manual
86
Direct Drives & Systems
Chapter C: System functions ETEL Doc. - Operation & Software Manual # DSC2P 903 / Ver. F / 3/6/05
new data. If this new value is incorrect, the K79 BAD VALUE error (M64=40) will appear.
For the DSCDP, if parameter K79 is modified (with K79=100, 101 and 104), the SAV command
must be executed on both axes. For the DSCDP, K79 = 4 and 104 is available only from
DSCDP3xx-xxxE. For the DSCDL, K79 = 4 is available only from DSCDL3xx-xxxC.
Parameter K55 allows the setting of the number of increments per magnetic period (linear motors)
or per turn (rotary motor); this parameter is used by the motor commutation look-up table (LKT).
Monitoring M239 indicates the encoder period given either by parameter K241 or the EnDat 2.1
encoder (depending on the encoder type selection (parameter K79)).
The currents sent to the motor phases are calculated by the current reference generator with the commutation
look-up table. Here is the formula to calculate the number of increment (parameter K55):
•For rotary motor:
•For linear motor:
Remark: Refer to §13.3.10
and §13.10 for more information about parameters K69 and K77 and to
§13.3.10
for parameter K50.
Monitoring M241 indicates the encoder interpolation factor.
12.3.1 Analog encoders (K79=0)
The analog encoders (1Vptp) can determine exactly the motor position thanks to two sinusoidal signals with
a phase-shift of 90° (sine and cosine). The period of these signals varies according to the type of encoder used
(from 128 nm to 32 mm). The smaller the period is, the bigger the precision is. These signals must be calibrated
to be optimized so as to have the same amplitude and no offset. Parameters K70, K71, K72 and K73 make
such corrections. Some of the scales used with the analog encoders are multi-reference mark, and in that case
the average distance between reference marks must be given via parameter K75. Formula for linear motors:
M Name Comments
M239 Encoder period Gives the type of motor connected to the position controller
M Name Comments
M241 Encoder interpolation factor
Gives the interpolation factor of the encoder.
In the above-mentioned formulas, monitoring M241 corresponds to
1024 * 2
K77
(for an analog encoder) and 64 * 2
K69
(for a TTL encoder).
Available on DSC2P DSC2V DSCDP DSCDL DSCDM
K55 NPCod 1024 2
K77
⋅⋅=
NPCod = Encoder periods number per turn [p/r]
(for analog encoder)
K55 NPCod 64 2
K69
⋅⋅=
(for TTL encoder)
K55
Pway
PCod
----------------
1024 2
K77
⋅⋅=
PCod = Encoder periods number [m]
(for analog encoder)
K55
Pway
PCod
----------------
64 2
K69
⋅⋅= (for TTL encoder)
Pway = magnetic period [m]
K75
1024 Distance between 2 indexes [m]
⋅
PCod
--------------------------------------------------------------------------------------
with PCod = encoder period [m]=

Etel DSC Series Specifications

General

Brand	Etel
Model	DSC Series
Category	Controller
Language	English