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Control Systems
OBR Control Systems Inc
OBR Control Systems Inc
Telephone : +1 (248) 672-3339
32233 West 8 Mile Road
www.obrcontrolsystems.com
Livonia, Michigan 48152
USA
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8.2 Analogue Inputs
PCM2 has 16 analogue 0..5V sensor inputs with a 10 bit resolution and sampled at typically 10 Hz.
Furthermore, these inputs can be grouped to create 8 differential inputs (not implemented yet).
Input names can be up to 15 characters long.
Analogue signals below 100mV are displayed as 0.
Click on the number button to the left of the analogue channel
name to open the visualisation
display.
See section 8.
Analogue inputs can be assigned having different characteristics:
Pull-up to VREF through a 3.16 kOhm resistor (only intended for use with NTC temperature
sensors)
Pull-up to VREF through a 47 kOhm resistor (allows detection of broken sensor wires)
Floating input – preferred selection for all sensors except NTC temperature sensors.
Section
Conversion
gives access to a linearization table having 32 breakpoints. Any number of
breakpoints can be used; a 2-point calibration of a pressure sensor only requires two.
If a sensor A/D value is below the minimum breakpoint, the minimum value is applied.
If a sensor A/D value is above the maximum breakpoint, the maximum value is applied.
Leaving all breakpoints at 0 (zero) channel values are displayed in millivolts.
The “In Value” is entered in millivolts.
Sensor scaling is normally entered in for example millibar, millilitres, milliampere etc.
Sensor channel values are displayed in real time in millivolts if the calibration table is left blank.
If the calibration table is used, the value displayed is the converted channel data.