Definition - What does Heartbeat Cable mean?
A heartbeat cable is a specific piece of hardware used to connect multiple servers in a process called failover. In this kind of setup, the heartbeat cable handles a "pulse", or recurring signal from the first server to the second server. If the first server encounters a problem, the second server can be programmed to assist when the heartbeat from the cable is interrupted.
Techopedia explains Heartbeat Cable
Part of the issue with using a heartbeat cable involves accurate configuration. In many cases, a cable can be connected from "RF out" to "RF in" on two servers, but there may be complications. Installers may need to read relevant manuals to figure out, for example, how to ensure a particular display result for hardware status.