Watlow D4T Data Logger
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Chapter 5 Function Reference
Universal Input
Use this block to condition a temperature measurement made with a thermocouple or RTD or
another analog process signal. Refer to the sections below for descriptions of the Universal In-
put and each sensor type it supports:
: overview of this block.
Scaling Voltage and Current Inputs to Process Units
: overview and example of linear scaling of
process inputs.
: use this sensor type to measure and condition and scale a voltage input.
: when set to off, the FB will be in error (Not Sourced).
: use this sensor type to condition a temperature measurement made with a
thermocouple.
: use this sensor type to measure, condition and scale a voltage input.
: use this sensor type to measure, condition and scale a current input.
: use this sensor type to condition a temperature measurement made with an
RTD.
: use this sensor type to condition a temperature measurement made with an
RTD.
: use this sensor type to measure and scale a resistance input.
: this section describes the errors that may occur on the signal supplied
by the Universal Input function block.
About the Universal Input
The Universal Input block scales the electrical signal received by the analog input hardware
to a process value that can be used by other blocks such as an alarm. If the signal is from a
thermocouple or RTD, once the Sensor Type, TC Linearization and RTD Leads parameters are
set, the block scales the signal to an absolute temperature with no other configuration re-
quired.
Note:
Flex Modules can be ordered as Mixed I/O or High Density (HD) I/O. When HD modules are
in use, the pinouts on the card are slightly different than Mixed I/O modules. Pinouts and
the associated graphics are displayed for both.
Note:
Although the functionality and parameters for any given sensor type does not change with
the selected Units, the graphic does. In the following descriptions, the associated graphics
for the sensor type will be displayed for the selected units.
Scaling Voltage and Current Inputs to Process Units
If the signal is from a device that outputs a voltage or current proportional to the process val-
ue, set the Sensor Type, Units, Scale Low, Scale High, Range Low and Range High parameters
to present the process value in the appropriate units. Scale Low and Range Low are the coor-
dinates of one point and Scale High and Range High are the coordinates of another point de-
fining the line relating the electrical signal to the conditioned process value produced by this
block. See the figure below.
