IMC CANSAS - Incremental Encoders; Signals and Conditioning

190 Measurement Technique
imc CANSAS Users Manual - Doc. Version 1.9 - 05.12.2014© 2014 imc Meßsysteme GmbH
5.1.3 Incremental Encoders
The four incremental encoder channels of CANSAS-INC4are for measuring time or frequency-based
signals. In contrast to the analog channels as well as to the digital inputs, the channels are not sampled at
a selected, fixed rate, but instead time intervals between slopes (transitions) or number of pulses of the
digital signal are measured.
The counters used (set individually for each of the 4 channels) achieve time resolutions of up to 31 ns
(32 MHz); which is far beyond the abilities of sampling procedures (under comparable conditions). The
sampling rate which the user must set is actually the rate at which the system evaluates the results of the
digital counter or the values of the quantities derived from the counters.
5.1.3.1 Signals and Conditioning
5.1.3.1.1 Mode
The various modes comprise the following measurement types:
Event-counting
Time
Combined measurements
events
distance(differential)
angle (differential)
distance (abs.)
angle (abs.)
time
pulse time
PWM
frequency
speed
RPM
5.1.3.1.1.1 Event-Counting
The following variables are derived from Event counting:
events
distance(differential)
angle (differential)
distance (abs.)
angle (abs.)
The amount of events occurring within one sampling interval is counted. The event counter counts the
sensor pulses within the sampling interval. An event is a positive edge in the measurement signal which
exceeds a user-determined threshold value.
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