GE VersaMax, Manual

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GFK-1504K Chapter 10 Analog Input Modules 10-15
10
IC200ALG240
Analog Input Module, 16 Bit Voltage/Current, 1500VAC Isolation, 8 Channels
Configuring Scaling
The module converts electrical signals (either current or voltage, as configured) into digital
output values for the CPU or NIU. By default, the module converts this data from 1
millivolt or 1 microamp “internal units” for convenience in scaling and comparing to
actual meter measurements.
The module’s default scaling can be changed to tailor the data for a specific application.
Typically, engineering units represent millivolts or microamps. But they may also
represent physical units such as degrees or centimeters per second. When reconfiguring
scaling, it is important to be sure that the chosen Engineering Units values would not result
in Overrange or Underrange output levels.
The scaling for each channel can be configured independently. Scaling is configured by
selecting corresponding low and high engineering units values and low and high internal
values (counts) for two points.
During operation, the module will use the straight line defined by these two pairs of
configured scaling values to convert internal values to current or voltage signal levels that
represent appropriate engineering units.
Scaling Values for 1mV or 1
µ
A Engineering Units
For many applications, the engineering units are either millivolts or microAmps. These
units are easy to scale. Simply use the table below to find scaling values that are
appropriate for the channel’s configured range.
Examples Input
Range
Enter this engineering
units value
Span Units
(microAmps)
4 mA to 20 mA 4 mA
20 mA
Low +4,000
High +20,000
Low +4,000
High +20,000
-10 volts to +10 volts 0 volts
+10 volts
Low 0
High +10,000
Low +4,000
High +20,000
0 mA to 20 mA 0 mA
20 mA
Low 0
High +20,000
Low 0
High +20,000
-10 volts to +10 volts -5 volts
+10 volts
Low -5,000
High +10,000
Low -5,000
High +10,000
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