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<< Click to Display Table of Contents >> Item designations in the drawing sheets |
  
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<< Click to Display Table of Contents >> Item designations in the drawing sheets |
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Figure 358: The "Item designations in the drawing sheets" section
There are two main ways of presenting item designations in a circuit diagram. They both correspond to the current IEC standard. If you consider a complete item designation such as =A1+E1-K1, it can be written either in a single line or in many lines, separate for the three involved aspects. The function =A1 can be placed on the top line, the location +E1 in the middle line, and the product –K1 in the bottom line.
Both these ways of presenting an item designation are correct. The standard specifies that the item designation should be placed to the left of the symbol in a vertical circuit diagram, and above the symbol in a horizontal circuit diagram.
The standard symbols of the IEC1082 symbol library, which supports the current IEC/DIN standard, use separate attributes for plant (function), location, and designation (product or complete item designation dependent on the configuration). A complete item designation including plant and location can be defined in the designation attribute, which will then be interpreted correctly by cadett ELSA.
It is also possible to add a plant designation in the plant attribute and a location designation in the location attribute in order to complement the designation part in the item designation attribute.
So-called redundancy reduction can also be applied, so that plant and/or location designations which correspond to either the title field or surrounding boundary boxes, are reduced, meaning that they are removed when they are not needed.
There are four different options for how the OnLine Engine should handle these cases. You can choose which one of them to use, by selecting the associated radio button.
Option |
Description |
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Always in one single line |
The Always in one single line option means that specifying the entire item designation with all its aspects in one single line, with or without redundancy reduction, is the only way of presentation that is allowed. If you enter an item designation divided in several lines, it will automatically be assembled into one line. That is done directly in the dialogue, when you enter the item designation, and in connection with any possible changes, even if they are made from the outside, like through the Dynamic OnLine.
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Always in separate lines |
In a corresponding way, Always in separate lines means that item designations are always specified with the tree aspects in separate lines. If you enter an item designation in one single line, it will automatically be divided in many lines.
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Auto (both alternatives allowed) |
Auto (both alternatives allowed) means that both ways of specifying item designations are supported simultaneously. If you specify an item designation divided into several lines, and then change it in some way, like directly in the dialogue or through the Dynamic OnLine, the original way of presentation will be kept. The same is also true if you use one single line.
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Unreduced single line designations only |
A fourth special option is Unreduced single line designations only, which means that all settings for so-called "redundancy reduction" are ignored and all item designations are presented in one single line in the item designation attribute, complete with both plant and location, irrespective of any boundary boxes or title field specifications.
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Please note that all examples described above refer to a classic item designation composition with function, location and product in that order. If you use other variations, the general principles are still the same, even if the item designations will look somewhat different.