Allen-Bradley ControlLogix Ethernet Driver Help
Complex Example Logix Tag is defined with address "Local:1:O.Slot.Data". This would be represented in the groups "Local:1:O"
> "Slot". Within the last group would be the tag "Data".
The static reference to "Data" would be "Channel1.Device1.Local:1:O.Slot.Data". The dynamic reference would be "Channel1.Device1.Local:1:O.Slot.Data".
Note: I/O module tags cannot be directly imported in Offline mode. Since aliases can be imported, it is recommended that they be created for I/O module tags of interest in RSLogix5000.
Controller-to-Server Name Conversions
L e a d i n g u n d e r s c o r e s " _ " i n t a g o r p r o g r a m n a m e s w i l l b e r e p l a c e d w i t h " U _ " . T h i s i s r e q u i r e d b e c a u s e t h e s e r v e does not accept tag or group names beginning with an underscore. r
Long Names (OPC Server Version 4.64 and below)
Under older OPC server versions, the Allen-Bradley ControlLogix Ethernet Driver was limited to 31 characters in group and tag names. Therefore, if a controller program or tag name exceeded 31 characters, it had to be clipped. OPC server Version 4.70 and above has a 256 character limit, so the rules do not apply. Names will be clipped as follows:
Determine a 5-digit Unique ID for this tag.
Given a tag name: ThisIsALongTagNameAndProbablyExceeds31
Clip tag at 31: ThisIsALongTagNameAndProbablyEx
Room is made for the Unique ID: ThisIsALongTagNameAndProba#####
Insert this ID: ThisIsALongTagNameAndProba00000
Determine a 5-digit Unique ID for this array.
Given an Array Tag name: ThisIsALongTagNameAndProbablyExceeds31_23_45_8
Clip tag at 31 while holding on to the element values: ThisIsALongTagNameAndPr 23 45 8
Room is made for the Unique ID: ThisIsALongTagName##### 23 45 8
Insert this ID: ThisIsALongTagName00001 23 45 8
Long program names are clipped in the same manner as long non-Array Tag names. For every tag or program name that is clipped, the Unique ID will be incremented. Array Tag names (elements) of a clipped array name will have the same Unique ID. This provides for 100000 unique tag/program names.
Note: If the "Limit Tag/Group Names to 31 Characters" setting is enabled, the following rules apply even if the 256 character names are supported. For more information, refer to Logix Database Options.
Preparing for Automatic Tag Database Generation For information on using Automatic Tag Database Generation, follow the instructions below.