Ax58 ISI
6 - Functions
6.1 Operating modes
"Real-time mode"
In this mode the frequency of output signals is
proportional to the encoder speed. Pulse distance
changes in respect to the encoder speed. The max.
counting frequency in "Real-time mode" is FRT (see
Tab.1).
"Burst mode"
The encoder switches to this mode if the counting
frequency is higher than FRT. In order to speed up all
counting operations the microprocessor outputs all
pulses at a constant frequency FBM (see Tab.1). In
this case the encoder position (information from the
optical disc) is not equal to the current position. The
encoder will store the difference in a register and
balance it (recovering the difference between
encoder- and actual position) as soon as it switches
back to "real-time mode".
The time to recover current position depends on
how long the encoder works in burst mode. The
shorter the burst mode time the shorter the time to
recover current position.
NOTE:
If the encoder shaft is stopped while working in
burst mode it will still output a certain quantity of
pulses in order to recover it's position.
ATTENTION !
It's recommended not to use ISI encoders for
dynamic speed control while working with "burst
mode".
Tab. 1
Type Start-up
freq. FST
Real-time
freq. FRT
Burst mode
freq. FBM
AS58 ISI 1,2 kH < 100 kH 100÷120
kH
AM58 ISI 80 kH < 20 kH 20÷56 kH
6.2 Singleturn version (AS)
Enable (input)
Enables or disables the encoder. Delay time between
input activation and signal output is 400 msec.
•Input high (+10Vdc +30Vdc): encoder disabled.
No pulse output. A and B are high, 0 is low.
•Input low (0Vdc): encoder enabled. Position
output after 400 msec. A and B give out current
position by means of a pulse train. After
transmission of the pulse train the output
signals are the same like an incremental encoder.
0 give out a index signal.
Zero setting (input)
Sets the encoder's current position to ero (0).
•Input high (+10Vdc +30Vdc) : ero setting
•Input low (<8Vdc) : function not enabled
Complementary (input)
Allows to change counting direction by means of an
input signal.
•Input high (+10Vdc +30Vdc) : ccw counting
•Input low (<8Vdc) : cw counting (standard)
Error (output)
Indicates if any error occurs to the encoder while
processing data.
•Output high (+10Vdc +30Vdc) : no error
•Output low (0Vdc) : error
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MAN Ax58x ISI I_E 1.1 Pag. 7 www.lika.it
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