Data Refresh Rates
When choosing the frequency of your fieldbus protocol (such as RPI or repetition rate) or the frequency of updating acyclic data in your PLC program, it is important to understand the frequency of the data updates on the island itself.
For instance, Active Energy data is updated every 100 ms. So it is not useful for the PLC program to update this acyclic data every 10 ms. However, all outputs (starters, digital outputs, analog outputs, trip resets, and other resets or presets) are updated at a frequency of <10 ms. Inputs are updated at various frequencies depending on their importance.
See the table below for more information.
Data Refresh Rates
| Data | Maximum update interval |
|---|---|
|
Input and output status of power devices, digital I/O modules, and SIL* interface modules for example, Run commands, contactor status (RunFwd, Tripped), digital input (DI0, DI1…) |
10 ms |
|
Analog measurements of power devices, analog I/O modules, and voltage interface modules for example, phase current (AvgIRMS, PhaseXIRMS), phase voltage (VRMSPhaseX, AvgVRMS), power (InstActivePower, InstReactivePower, PowerFactor), energy (ActiveEnergy, ReactiveEnergy), analog inputs (MotorTemperature, AI0, AI1) |
100 ms |
|
Other data for example, asset data: ContactorCycleCntr, TimeModuleOn, AvgIRMS (lifetime) |
10 ms |