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Getting Started
Analog Input Terminology
We use several different terms throughout the rest of this manual. You don’t have to
be an expert on analog terms to use the products, but it may help make it easier to
select the appropriate modules if you take a few minutes to review these definitions.
The number of analog channels or points available in the module to connect to field
devices.
The input ranges in voltage and/or current that the module will operate properly
within.
The number of binary weighted bits available on the digital side of the module for use
in converting the analog value to a digital value.
Specifies if the module accepts single ended, bipolar or differential input signals.
The input impedance of the module using a voltage or current input signal.
The method the module uses to convert the analog signal to a digital value.
The amount of time required to complete the analog to digital conversion.
The linearity and accuracy of the digital representation over the entire input range.
The effect of temperature on the accuracy of the module.
LED indicators on the module
The number of I/O points the CPU must dedicate to the module.
Some modules require a separate 24VDC power source. The 24VDC output supply
at the local or expansion base can be used as long as you do not exceed the current
rating.
The amount of base current required by the module. Use this value in your power
budget calculations.
The minimum and maximum temperatures the module will operate.
The minimum and maximum humidity the module will operate.
Indicates whether the terminal type is a removable or non-removable connector or a
terminal.
The weight of the module.
Channels per
Module
Input Ranges
Resolution
Input Type
Input Impedance
Conversion
Method
Conversion Time
Linearity Error and
Total Tolerance
(Relative Accuracy)
Accuracy vs.
Temperature
LED Display
I/O Points Required
External Power
Source
Base Power
Required
Operating
Temperature
Relative Humidity
Terminal Type
Weight