Rockwell Automation Energy Management Accelerator Toolkit Quick Start - Manual (Page 441)

Rockwell Automation Publication IASIMP-QS016C-EN-P - October 2014 441
Digital and Analog Energy Add-On Instructions Appendix D
CompactLogix Analog Input Logic
The following Logic is provided in all the Energy_ xxx_Analog Add-On Instructions to calculate energy consumption from
corresponding CompactLogix analog inputs. The Inp_Meter_Analog_Value tag is the instantaneous energy flow value
from the CompactLogix analog input.
To calculate total flow, an instantaneous flow value is calculated every 250 ms and is stored as Buffered_Flow. This value is
then included in the Val_Total_xxx, total consumption. For very small instantaneous flows, a comparison between the new
Val_Total_xxx and the previous Val_Total (Temp_Buffer) is performed by using the NEQ instruction. If the two values are
not equal the Buffer_Flow is cleared.
When the total value equals 10 million, the rollover rung resets the total energy value, Val_Total_ xxx.