Cjc (c – Omega Vehicle Security OMP-MODL User Manual
Page 167
11.. . A
PPENDIX
A: M
ASTER
I
CON
R
EFERENCE
U
SING THE
OMP-MODL
11-5
CJC (C
OLD
J
UNCTION
C
OMPENSATION
) I
NPUT
I
CON
:
FUNCTION:
Performs the Cold Junction Compensation (CJC) channel selection, amplification, and
A-D conversion for a thermistor hardware input from a sensor mounted by the terminal
strip header on the inside of the MLAD-1.).
Alternatively, the CJC icon can be used to take a resistance reading or measure the
temperature of an external thermistor (10Kohm at 25C, Fenwall curve 16 or equivalent).
A wire jumper on the terminal strip can be removed and external wiring added if this
optional use is desired. Due to the optimization of the CJC circuit for temperature
sensing, the resistance measurement capability of this circuit does not provide consistent
linearity over the full range. The normal resistance measuring range for a thermistor is
200 ohms to 70,000 ohms.
NOTE: If Thermocouple icons are used in the Program Net, the external sensing function
described above must not be used as the temperature of the terminal strip is critical in the
calculation of thermocouple temperatures.
INPUTS:
Hardware: No signal input shown on Net for Program Net connections.
Update Clock:
Output is updated with new reading upon each Update Clock pulse
when Enable input is unconnected or Hi.
Enable:
Processing of icon is allowed when Enable pin is unconnected or connected
and Enable signal is TRUE.
OUTPUTS:
Output Signal:
Data type signal. The Units of the output are degrees C or F, or
ohms, selectable from the icon configuration dialog box..
ICON CONFIGURATION DIALOG BOX:
CONFIGURATION OPTIONS:
Icon Name: Specify the name for the channel. This name will show directly under the
icon within the Program Net.
Output Name:
Specify a name for the Output signal from this icon. This Output
Name will be referenced by other icons downstream in the Program Net.
Units:
Specifies the temperature scale units that will be output from this icon.
Celcius, Fahrenheit, and Ohms are directly supported.