Drawing Environment > Detailed command descriptions > Symbol Generator > Example > Creating a symbol from an existing one > Component type, Resource category and Function code

•The Component type letter code is the letter that is included in automatically generated item designations, like when you insert a main symbol. This might for instance be “M” for a motor, where “-M1” is an example of an automatically generated item designation. Please note that help symbols normally do not have component type letter codes.

•The Resource category defines where the symbol is presented in the Symbol Insert Tool. It is also used for filtering towards the Catalogue. Sometimes this letter corresponds to the component type letter code, but that is not always the case.

•Main symbols normally do not have a Function code, while help symbols and mirror symbols always have one. As an example of this we can take a help contact. There are several kinds of help contacts. The function code tells what kind we are dealing with. It might for example be a make help contact, a break help contact, a delayed make help contact or something else, only to mention a few.

In the example with the laser siren, you may use the letter H for both component type letter code and resource category, which corresponds to the old IEC750 standard, the predecessor to IEC1346. If we want to comply with IEC1346, we easily end up in a discussion about the use of laser sirens, since IEC1346 focuses on function when component type letter codes are concerned. Tentatively we avoid that discussion here since we are dealing with a figment of the imagination.

(Devices such as signal lamps, bells, and horns, which are used to present information however belong to component type letter code P according to IEC1346).