MAN0974-13.1-EN_XL7_UM
August 19, 2021
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9.3 High Speed Counter (HSC) Functions
The XL7 supports two very high speed, configurable counters. There are four dedicated inputs
that can be configured to a number of different options. Each of the two counters can run in
one of five modes. Those modes are Totalizer, Frequency Counter, Pulse Width Measurement,
Period Measurement and Quadrature measurement. For some modes, more than one HSC
input may be consumed. The measurement values are provided to ladder in a %AI register.
Refer to the
9.3.1 Frequency
In frequency mode, the frequency of the input signal is written to the accumulator in terms of
Hertz (cycles/second). When using frequency mode, four update selections are provided
which specify the width of the sample window.
NOTE: Selecting a shorter sample window provides a quicker measurement (faster response)
but lowers the frequency accuracy (resolution) and increases the minimum frequency
measurement limit. In this mode the Disable and Latch special functions are allowed. Refer to
the
for a description of these functions.
