Rockwell Automation Energy Management Accelerator Toolkit Quick Start - Manual (Page 433)

Rockwell Automation Publication IASIMP-QS016C-EN-P - October 2014 433
Energy Electric Add-On Instructions Appendix C
CompactLogix Analog Input Logic
The following logic is included in the Energy_Electric_Analog Add-On Instructions to calculate the total kWh electric
consumption from a CompactLogix analog input.
The Inp_Meter_Analog_Value tag is the instantaneous electric value from the CompactLogix analog input. To calculate
total kWh, the instantaneous electric value is calculated every 250 ms and stored as Buffered_Flow. This value is then
included in the Val_Total_kWh, total consumption. For very small instantaneous values, a comparison between the new
Val_Total_kWh and the previous Val_Total_kWh (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 Val_Total_kWh value.
Rollover Rung