GFK-1504N
Chapter 11 Analog Output Modules
11-55
11
IC200ALG331
Analog Output Module, 16 Bit Voltage/Current, 1500 V AC Isolation, 4 Channels
Configuring Scaling
The module converts digital output values received from the CPU or NIU to
electrical signals (either current or voltage, as configured). By default, the
module converts this data to 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 output data to 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
Output
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
