The NL304 Period Generator contains a crystal oscillator and frequency dividers for producing a precise, stable frequency standard. It can be externally gated (GATE IN) and synchronised with an external source (RESET input). The pulse train can be switched off and a single output pulse can be produced manually by a front panel push switch.
The NL304 is the basic “clock” of the NeuroLog System as it provides the “fine grain” (1 microsecond increments) necessary for digital control of pulse width, cycle duration, delay, etc. using the NL603 counters.