DirectLogic Data Address

Introduction

In DirectLogic PLC Devices, data is stored different different locations depending on the intended use of the data. For example:

Inputs
Outputs
Timer values
Data registers

The DirectLogic Data Address is a text string that defines the location of an item of data in a DirectLogic PLC. Fernhill SCADA uses the text string to locate items of data in the PLC.

DirectLogic Data Address

The DirectLogic Data Address consists of one or two device letters followed by a zero-based octal number:

Data	Format	Notes
Inputs	Xnnnn	Bit values
Outputs	Ynnnn	Bit values
Control Relays	Cnnnn	Bit values
Special Relays	SPnnnn	Bit values
Timer Values	TVnnn	16-bit words
Timer Status	Tnnn	Bit values
Counter Values	CVnnn	16-bit words
Counter Status	CTnnn	Bit values
Data Words	Vnnnnn	16-bit words

Note: The numbers nnnn are octal and zero-based.

Where Used

The DirectLogic Data Address is used in these contexts:

In the IOItemName property of an I/O Analog Data Point Tag when the tag is associated with a Modbus Device.
In the IOItemName property of a I/O Digital Data Point Tag when the tag is associated with a Modbus Device.
In the IOItemName property of a I/O Word Data Point Tag when the tag is associated with a Modbus Device.
In the IOItemName property of a I/O Double Word Data Point Tag when the tag is associated with a Modbus Device.
In the IOItemName property of a I/O Long Word Data Point Tag when the tag is associated with a Modbus Device.
In the Register property of a Modbus Register Block.
In the DataAddress parameter of the DirectWriteBit Tag Command when used with a Modbus Device.
In the DataAddress parameter of the DirectWriteWord Tag Command when used with a Modbus Device.

Data Address Editor

The Data Address Editor is a convenient tool to build an Enron Modbus Data Address.

To open the Data Address Editor, click the Browse button of the IOItemName or Register property:

Further Information

Modbus Device Tag

To learn about Modbus Device Tags.

Modbus Register Block Tag

To learn about Modbus Register Block Tags.

Modbus Driver

For an overview of the Modbus Driver.

Glossary

For the meaning of terms used in Fernhill SCADA.