Allen Bradley Logix PLC Data Address

Help Contents

Introduction

Allen Bradley Logix PLC models include:

These types of PLC are configured using IEC 61131-3 and store data in named variables.

To access data in a Logix PLC, Fernhill SCADA uses this format of data address:

Variable[VarArrayIndexes].StructMember[ArrayIndex].BitNumber

Where:

Variable Reference Examples

Some examples of Allen Bradley Variable References:

AddressDescription
FlowTemperatureA reference to a variable called FlowTemperature.
FlowTemperatures[2]A reference to array element 2 of a variable called FlowTemperatures.
SCADAData.PressureA reference to Pressure member of the variable SCADAData.
SCADAData.StateFlags.5A reference to bit 5 of the StateFlags member of the variable SCADAData.

Where Used

This type of data address can be used in these contexts:

Further Information

Allen Bradley PLC File Data Address

To learn about accessing data in an Allen Bradley file based PLC.

Allen Bradley Register Block Tag

To learn about Allen Bradley Register Block Tags.

Allen Bradley Driver

For an overview of the Allen Bradley Driver.

Glossary

For the meaning of terms used in Fernhill SCADA.