Direct Variable User Programming Memory

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User Direct Variable Memory variables are defined as follows:

There are 2 main memory locations for User assignment: M and W. Each memory area is defined through direct variables by data type. The only difference in the Memory area is the retain setting.

For Modbus TCP communications, a direct memory address variable is required for data transfer.

If using variables in the same memory area with a different data type designator, ensure that each variable is referencing a unique memory address, or data could be written over (See example below).

Configurable Retain

These registers can be configured for RETAIN setting in the Basic Parameter area of the project window.

Memory Area	Data Type Designator	Direct Variable Tag by Data Type
M	X (bit) 1 BIT	%MX0 -%MX262143
	B (byte) 8 bits	%MB0 -%MB32767
	W (Word) 16 bits	%MW0 -%MW16383
	D (Double Word) 32 bits	%MD0 -%MD8191
	L (Long Word) 64 bits	%ML0 -%ML4095

Always Retain

These registers will always retain their value.

Note: In the LS Documentation, there is reference to W and R memory locations. These are the same physical memory location. ADC recommends using the W memory address. Do not use R.

Memory Area	Data Type Designator	Direct Variable Tag by Data Type
W	X (bit) 1 BIT	%WX0 - %WX542287
	B (byte) 8 bits	%WB0 - %WB65535
	W (Word) 16 bits	%WW0 - %WW32767
	D (Double Word) 32 bits	%WD0 - %WD16383
	L (Long Word) 64 bits	%WL0 - %WL8191

 

 

 

 

 

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