X90 mobile modules
160
X90 mobile system User's manual V 1.20 - Translation of the original manual
5.4.1.5.5 Analog input functions
Each of the module's 4 accelerometer inputs can also be used directly as an analog input with various special
functions (see register
"AnalogInput" on page 161
).
The resolution of the analog inputs can be set using the configuration (
"AnalogInputScale" on page 164
). The
lower the maximum value, the higher the resolution of the register and vice versa. When the maximum value is
exceeded, the register is limited to the respective maximum (positive or negative).
A toggle bit (AnalogInputToggleBit01-04) signals when a new value has been transferred.
The following functions are available:
•
Normal analog input function
•
Characteristic value calculation in continuous mode with enable (continuous mode)
•
Characteristic value calculation in trigger mode (single shot)
5.4.1.5.5.1 Measured values
The last 8 measured values before the X2X cycle are always averaged and transferred on the bus. Here, the direct
input signal (raw signal max. 10 kHz) with a sampling frequency of 25.781 kHz is always used and is not mean-
adjusted. The value is scaled according to the configuration. (See register
"AnalogInputScale" on page 164
.)
5.4.1.5.5.2 Characteristic value calculation in AnalogInput
The following characteristic values can be displayed directly in register
"AnalogInput" on page 161
. In this case,
it is necessary to check the configured scale.
•
Mean
•
Peak value (absolute)
•
RMS value
•
Crest factor
There are 2 signals available to calculate the configured characteristic values:
•
Input signal filtered to 10 kHz with a sampling frequency of 25.781 kHz and not mean-adjusted.
•
Raw signal filtered to the maximum frequency with a sampling frequency that is dependent on the
"MaxFre-
quencyRaw" on page 186
configuration and with mean adjustment using the last 8192 samples.
Register
"SamplesAnalogInput" on page 165
can be used to set how many sampled values should be used to
calculate the respective parameter. The time between 2 samples depends on the maximum frequency.
2 modes are available:
•
"Continuous mode with enable (continuous mode)" on page 161
•
"Trigger mode (single shot)" on page 161
