Etel DSC Series User Manual

Operation & Software Manual
88
Direct Drives & Systems
Chapter C: System functions ETEL Doc. - Operation & Software Manual # DSC2P 903 / Ver. F / 3/6/05
12.3.2 EnDat 2.1 encoders (K79=4)
The EnDat 2.1 encoders (analog 1Vptp) can determine the absolute position of the motor thanks to two
sinusoidal signals with a phase-shift of 90° (sine and cosine) and the information given by its two serial lines
(clock and data). 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.
Caution: Be careful of the length (max. 150m with distributed capacitance 90 pF/m) of the encoder cable
because the clock frequency of the EnDat 2.1 is equal to 500kHz. Refer to the encoder's
manufacturer for more information about the EnDat 2.1 encoder's cable.
Offset correction (K70, K71):
If parameter K70 or/and K71 is smaller than 0, a positive offset is added to the corresponding signal and a value
higher than 0 adds a negative offset. If parameter K70 or/and K71 is equal to 0, no offset correction is done.
Remark: Monitorings M40 and M41 allows the user to monitor the sine and cosine signals of the analog
encoder (refer to §12.3.7
for more information).
Amplitude correction (K72, K73):
The amplitude correction only allows the decrease of the signal amplitude and never the increase of it. That is
why, the encoder head tuning is highly important because it will not be possible to correct a too weak
amplitude with the software. It is possible to decrease a signal amplitude at best by a factor 2 with the value
16384. The value 32767 does not correct any encoder signals amplitude.
Remark: During offset and amplitude corrections manual research, it is advised to start first disabling
individually every signal offset, and then to correct the amplitudes in order to adjust the bigger on
the smaller.
Parameter K75 does not exist with K79=4 contrary to K79=0.
Available on DSC2P DSC2V DSCDP DSCDL DSCDM
Sensor amplitude
Signal without offset correction
K70 and K71 = 0
Signal with offset correction
K70, K71 between -1024 and 1024
bigger than 0 ⇒ move down
smaller than 0 ⇒ move up
Position
Sensor amplitude
Signal without amplitude correction
K72, K73 = 32767
Signal with amplitude correction
for adjusting, value is included
between 32767 (·1) and 16384 (·1/2)
A
A / 2
Position
Sensor amplitude
Signal without amplitude correction
K72, K73 = 32767
Signal with amplitude correction
for adjusting, value is included
between 32767 (·1) and 16384 (·1/2)
A
A / 2
Position

Etel DSC Series Specifications

General

Brand	Etel
Model	DSC Series
Category	Controller
Language	English