DDE/OPC predefined items

RSLinx Classic can obtain general processor information or trigger events using DDE/OPC predefined items.

The following are predefined items to use with all PLC types:

@Mode
returns the current mode of the processor as a string (Run, Program, Remote Run, or Remote Program).

@ProcessorName
returns the name of the program running in the processor.

@Revision
returns the firmware version of the processor as a string.

@PLCType
returns the processor type as a string.

@Status
returns the current status of the processor as a string (Ok or Faulted).

@StatusNumber
returns the current status of the processor as a number.

@SwitchTopic
is used to switch between alias topics in OPC clients.

The following are predefined items to use with

Logix 5000

family processors:

@FreeMem
returns total unused memory (I/O + data table + general, not applicable to Logix L8 controllers: ControlLogix5580, CompactLogix5380, and CompactLogix5480).

@FreeMemDT
returns unused data table memory (not applicable to 1756-L1 and Logix L8 controllers: ControlLogix5580, CompactLogix5380, and CompactLogix5480).

@FreeMemGM
returns unused general memory (applicable to 1756-L55M16 only).

@FreeMemIO
returns unused I/O memory (not applicable to Logix L8 controllers: ControlLogix5580, CompactLogix5380, and CompactLogix5480).

@TotalMem
returns total available memory (I/O + data table + general, not applicable to Logix L8 controllers: ControlLogix5580, CompactLogix5380, and CompactLogix5480).

@TotalMemDT
returns total available data table memory (not applicable to 1756-L1 and Logix L8 controllers: ControlLogix5580, CompactLogix5380, and CompactLogix5480).

@TotalMemGM
returns total available general memory (applicable to 1756-L55M16 only).

@TotalMemIO
returns total available I/O memory (not applicable to Logix L8 controllers: ControlLogix5580, CompactLogix5380, and CompactLogix5480).

@CLTagUpdateAddressSpace
forces RSLinx Classic to update its'

Logix 5000

tag database.

@RedundancyMode
monitors the processor state in a ControlLogix redundant system.

@IsPresent
allows you to check if your ControlLogix processor is available prior to performing reads or writes. The time out value is consistent with the communication timeout value in the configured PLC-5 topic.

Item syntax, addressing, and tips

Set the active topic configured in an alias topic

Update ControlLogix Tag Information

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