Absolute Multi-Turn Encoder - JVL MIS17 Series User Manual

5.8

Absolute Multi-turn Encoder

5.8.1 Introduction
Optional the MIS motors can be equipped with the absolute multi-turn encoder (MISxxx-
zzyyH3/H4nn option) which offers the possibility to keep track of the position regardless
if power is connected or not.
When this option is present a mechanical zero search is only necessary one time after
installation and the system will keep track of the actual motor position at any time after-
wards.
The encoder is based on a magnetic principle which do not offer the same resolution and
precision as the more expensive optical based solutions. It do however offer the advan-
tage to keep track of the position without power applied. The magnet principle is also
much more tolerant to mechanical stress such as shock and extreme temperatures.
The absolute multi-turn option offers the following main features.
Encoder:
Resolution
Accuracy
Repeatability
Position range
Motor:
Resolution
As seen above the motor resolution is much higher than the encoder resolution. The en-
coder option is however mostly used for stall detection at the motor (the motor loose
its position) and for this situation the encoder will be adequate since the motor can only
stall in multiples of a 1/50 shaft revolution corresponding to 7.2 mechanical degrees.
122 JVL Industri Elektronik A/S - User Manual - Integrated Stepper Motors MIS17x, 23x, 34x, 43x
409.600 counts per revolution displayed (internal 1024 cpr)
+/- 0,1% of full scale
+/- 0,1% of full scale
±5242 motor revolutions (+/- 2^31 motor counts)
409.600 counts per revolution (standard)
Only MISxxx---H3/H4--