An item type that is used for mediating between Smart Electrical and Smart Instrumentation. You can associate a signal with a load, a control station, or a circuit for the purpose of publishing data to Smart Instrumentation. You can perform wiring connections in Smart Instrumentation and retrieve the host information back to Smart Electrical, where it appears as read-only properties of the signal. Smart Electrical can then use the values of those properties to display I/O assignment information in a schematic.