GE VersaMax IC200CHS022 - Page 322

GFK-1504N Chapter 10 Analog Input Modules 10-7
10
IC200ALG230
Analog Input Module, 12 Bit Voltage/Current 4 Channels
Scaling
The following graphs illustrate the relationship between the input voltage or
current measured at the field terminals and the data that is output by the
module.
Count and Input Current
12.202mA
0 8192 16384 24576 32767
Count
24
20
16
12
8
4
0
mA
12.194mA
12.198mA
16408
16400
16392
16384
12.19mA
4µA = 8 counts
The following equation can be used to calculate counts values:
Counts = (Current in mA – 4mA) x (32768 / 16.35mA)
For a change in the reported count value to be seen, input current must be
increased by at least 4µA. If the module receives an increase less than 4µA, the
previous count value is still reported. For example:
Current
Count
12.190mA
16384
12.192mA
16384
12.194mA
16392