Omron PLC Data Address

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Data in Omron PLC Devices is stored different locations depending on the intended use of the data. For example, there are separate locations for I/O, Timer Values, Data Registers and so on.

The Omron PLC Data Address is a string that defines the location of data in an Omron PLC. It consists of optional device type letters, followed by one or more decimal digits:

Device Type Format Notes
I/O CIOnnnn[.bb]
The CIO prefix is optional. nnnn represents the I/O word. bb represents an optional bit number.
Link Relay LRnnn[.bb]
Used for a 1:1 link with another PLC
Holding Relay HRnnnn[.bb]
Value is retained when the power is turned off.
Data Memory DMnnnn[.bb]
Value is retained when the power is turned off.
Auxiliary Relay ARnnnn[.bb]
Timer Value Tnnnn
Timer Flag TSnnnn
Counter Value Cnnnn
Counter Flag CSnnnn
Expansion Data Memory EMmm.nnnn[.bb]
Only supported on the larger PLC Devices. mm represents the bank number

Note: The numbers in Omron PLC Data Addresses are zero-based.

Omron PLC Data Address Examples:

Address Description
0 The first word of the I/O area, for a modular PLC this is usually the first inputs.
1.15 The most significant bit of the second word of the I/O area.
10 The 10th word of the I/O area, usually the first outputs on a CPM1(A) or CPM2A.
CIO10 Alternative way of selecting the 10th word of the I/O area.
DM0000 The first Data Memory word, usually a user defined location.
EM00.100 Word 100 in Extended Memory Bank 0.

Where Used

The Omron PLC Data Address is used in these contexts:

Data Address Editor

The Data Address Editor provides a convenient tool to build Omron Data Address strings.

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

Omron Memory Address Editor

Further Information

Omron Register Block Tag

To learn about Omron Register Block Tags.

Omron Driver

For an overview of the Omron Driver.


For the meaning of terms used in Fernhill SCADA.