Eaton XN-312-GW-CAN, Manual

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7 Product-specific CAN objects XN300 slice modules
7.25 XN-322-1CNT-8DIO
Gateway XN-312-GW-CAN 06/16 MN050003-EN www.eaton.eu
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The maximum value that will result in the incrementing operation being
stopped must be entered into the MaxIdleTime register.
The quality of the measurement will depend on the entries in the idle clock
pre-scaler, the defined MaxIdleTime, and the number of pulses recorded in
the encoder idle time register. The goal is to use the register ranges opti-
mally while limiting the maximum time for the integration interval.
In regard to determining the rpm revolutions per minute, the encoder's reso-
lution with X1 encoding and, if applicable, the gear must be taken into
account. The following applies:
Timing diagram for the signals:
Signal A : Internal counter latch and restart if there is a rising edge. The inter-
nal IdleClock pulses are counted between two rising edges on signal A.
When the second edge occurs, the total value is copied to the encoder idle
time register and the internal counter is restarted.
Signal B : Positive direction of rotation if there is a rising edge on B after the
counter starts; negative direction of rotation if there is a falling edge on B
after the counter starts
Figure 87: Signal diagram for signals A and B
a Period counter
b Rising edge
c Positive value
d Falling edge
e Negative value
The signals are evaluated based on the X1 encoding for both signals (A and
B). If the signal sequence does not follow this method, the edge will not be
evaluated and the idle time register will report the maximum value -> motor
stop also if there is an open wire for signal A, A, B, or B.
Rpm = f
IPS * 60 [s/min]
Encoder resolution[i/r]
A
B
①
②
③
A
B
①
④
⑤