Need some info on digital counter display circuit?

Most frequency counters work by using a counter that accumulates the number of eventsthat occur within a specific period of time. After a predetermined period (1 second, forexample), the counter value is transferred to a screen and the counter is reset to zero. If the event is repeated measured with sufficient stability and the frequency is much smaller than the oscillator clock is used, the resolution of the measurement can be improved by measuring the time required for an integer number of cycles, instead of counting thenumber of complete cycles observed during a pre-set time (often referred to as the technique of reciprocity). The internal oscillator provides the timing signals is called the time base, and must be calibrated very accurately.

If you are already in electronic format, simple interface to the instrument is all that is required. More complex signals may need some fitness to be suitable for counting. Most of the Accountant General of the target frequency will include some type of amplifier, filter and the circuit configuration at the entrance. DSP technology, control of sensitivity and hysteresis are other techniques to improve performance. Other types of recurring events that are not inherently electronic in nature must be converted using some type oftransducer. For example, a mechanical event can be arranged to interrupt a light beamand the counter for counting the resulting pulses.

precision

The accuracy of a frequency counter is highly dependent on the stability of its time base. High precision circuits are used to generate this for instrumentation purposes, usually using a quartz crystal oscillator within a sealed temperature-controlled chamber known as an oven or OCXO crystal (crystal controlled oscillator oven). For more precisemeasurements, an external frequency reference oscillator connected to a high stability as a GPS disciplined rubidium oscillator can be used. When the frequency need not be known for a high degree of accuracy, simple oscillators can be used. It is also possible to measure the frequency using the same techniques in software on an embedded system. ACPU, for example, can be arranged to measure their own frequency of operation so long as there is some reference time base to compare with.
edit I / O interfaces

Interfaces I / S allows the user to send information to the frequency counter and receive information from the frequency counter. Interfaces include USB common use RS232, GPIBand Ethernet. In addition to sending the measurement results, an accountant can notify the user when the user defines the measurement limits are exceeded. Common to many accountants are the SCPI commands used to control it. A new development is integrated network-based control via Ethernet complete with GUI. This allows a computer to controlone or more instruments and eliminates the need to write SCPI commands.