Compatible Means that Two Things Work Together

Dictionary Definitions from Oxford Languages - - adjective: compatible

1. (of two things) able to exist or occur together without conflict. - Similar Wording: well matched, in agreement, in tune, reconcilable, accordant

In the Fire Alarm Codes, at least to paraphrase the codes, "Everything in a Fire Alarm System Must Work Together". That's Listed for Use, and that makes sense to me.

Compatibility, though, isn't really only being compliant to the code; compatibility is really a practical issue, an issue that produces an actually working fire alarm system; everything has to be compatible (work together) with everything else.

In essence, the codes are really just saying, "Let's be real . . . make sure everything works together to make a reliable fire alarm system."

Not in the Code

A list of compatibility list can't be found in the code. The people at the National Fire Protection Association (NFPA) or the International Fire Code (IFC) don't have the personnel and a huge laboratory to test all the fire alarm panels and all of the devices to see if they're compatible.

Instead, that testing is left up to the manufacturer, who delegates that testing to Third Party, Nationally Known Testing Laboratories, like UL, ULC, CE, FM, CCC, etc.

A testing laboratory tests the panels and all of the devices to make sure they all work reliably with each other. If they all work together, the testing laboratory places them on their List of devices and panels that are Usable with each other (Listed for Use).

In other words, when a fire alarm device is Listed for Use (those words are in the code) with a fire alarm panel, the device is compatible (works reliably) with the panel.

Also, when the Installation Manual shows a device or a panel is compatible, that combination has been tested by the testing laboratory to work reliably.