Global Data Performances

Introduction

The topic discusses Global Data performance.

Definition

Global Data return time:

This time corresponds to the elapsed time between the publication of a variable value by the local PLC application, the subscription by a remote PLC application, the publication of the same value by the remote PLC application, and the subscription by the local PLC application.

Values

Measurement conditions:

The cycle time for local and remote PLC applications are identical.
Only one variable is exchanged in each direction.

Result:

PLC cycle time	Return time
>= 10 ms	3 times the PLC cycle time
= 5 ms	5 to 6 times the PLC cycle time

Illustration: