heartbeat

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heartbeat

[′härt‚bēt]
(physiology)
Pulsation of the heart coincident with ventricular systole.

heartbeat

(networking)
The signal emitted by a Level 2 Ethernet transceiver at the end of every packet to show that the collision-detection circuit is still connected.

heartbeat

(2)
A periodic synchronisation signal used by software or hardware, such as a bus clock or a periodic interrupt.

heartbeat

(3)
The "natural" oscillation frequency of a computer's clock crystal, before frequency division down to the machine's clock rate.

heartbeat

(4)
A signal emitted at regular intervals by software to demonstrate that it is still alive. Sometimes hardware is designed to reboot the machine if it stops hearing a heartbeat. See also breath-of-life packet, watchdog.

heartbeat

(1) A periodic signal generated by hardware for activation and/or synchronization purposes. See MHz.

(2) A periodic signal generated by hardware or software to indicate that it is still running.