# Understanding layers in Eagle schematic window?

Eagle schematic editor is having the following default layers:

91 Nets: Nets
92 Busses: Buses
93 Pins: Connection points for component symbols
with additional information
94 Symbols: Shapes of component symbols
95 Names: Names of component symbols
96 Values: Values/component types
97 Info: General information
98 Guide: Guide lines


What is the purpose of the last 2 layers, info and guide in a schematic? Is it possible to have an example? Thanks.

## 3 Answers

I've never used the Guide layer, but have used the Info layer. Info is where I write comments in the schematic, names of the sheets, and anything else that isn't the parts or the connections between them.

I just flipped thru a recent schematic and found a note indicating the name of the firmware build that will go into a micro, a note by a inductor for the maximum allowed on time before saturation, and the text "Main circuit" and "Data interface" on opposite sides of a dashed line indicating isolation.

Think of Info in schematics as being similar to Docu, tDocu, and bDocu in boards.

In the EAGLE reference manual of version 5, the description of layer 98 is more clear:

98 Guide:    Guiding lines for symbol alignment


So, use this layer for all lines and forms you need to align the symbols in your schematic - and not for e.g. guidelines for assembly of the PCB.

The Info layer can be used as explained by Olin Lathrop: for any additional comments and information. I've also used that to describe what is attached to a connector, e.g. a motor or LED.

I would place information and explations about the schematic in layer 97. Instructions for assembley, testing, repairing on layer 98. Any information that would not fit to layer 91 to 96 should be placed in layer 97 and 98.