Frequency / Pulse rate to Analogue (current or voltage) Converters | Stroud Instruments

Applications:

The C16-10 has many uses in frequency to current / voltage converter applications including water and energy metering and rotational measurements.

Examples:

Conversion of flowmeter or water meter outputs Converts a water meter volt-free contact or open collector/drain into an analogue signal (e.g. 4-20mA, 0-10V, etc.) to provide a measurement of flow rate.

Monitoring engine speed or other rotational measurements The addition of a trip amplifier, provides overspeed alarms or safety shutdown.

Windspeed indication - Convert the pulse rate from an anemometer into e.g. a 4-20mA signal and with the addition of a digital panel meter, provide a display of windspeed.

User configurable

Optional PC configuration software provides range changing, e.g. to suit a turbine meter replacement, and optimisation of digital filtering to suit site conditions. The frequency to analogue converter is supplied either pre-calibrated to customers' specification (i.e. no further configuration required) or as a readily available item supplied with default settings for configuration by the user.

Analogue filtering

The level of input signal at which the frequency to analogue converter triggers is set by the front panel control.

Digital filtering

Digital filtering enables effective attenuation of noise yet permits a rapid response to a change in the input frequency. Factory-set default settings are suitable for many situations, however, the Programming software enables the characteristics of the digital filter to be modified by the following parameters:

Averaging Count: (digital filtering) Spurious input signals are attenuated by averaging the number of input measurements specified by the Averaging Count.
Change Threshold: To enable a rapid response to a change in the input signal, the most recent input measurement is continuously compared with the running average. If the change in input is greater than that specified by the Change Threshold parameter, the current averaging cycle is abandoned and a new one started.

Calibration

The output of the instrument may be scaled to the input signal frequency range with the following parameters.
Zero Scale Frequency: The input signal frequency required for ’zero’ output signal.
Full Scale Frequency: The input signal frequency giving full scale output signal.
Other parameters which effect the output are:
Static State Timeout: If the period in which the input signal remains unchanged exceeds this value, the current measurement is abandoned and the output signal cut to zero. In the event of a transducer or signal line failure, this facility ensures the output is not erroneously held at the last reading.
Minimum Threshold: The percentage of full scale below which the output signal is cut-off to zero.

Optional Programming Kit

Standard units are supplied with default settings (see the data sheet) ready for user configuration with the optional programming kit. Alternatively the C16-10 may be supplied pre-calibrated to user specifications.

The Programming Kit, comprising Windows™ compatible software and infrared USB link, provides adjustments to all the above parameters. It also enables input measurements (Hz) and output (% FS) to be displayed on screen.

Frequency to Analogue Converter, C16-10

...provides a mA or voltage output proportional to the pulse rate / frequency of the input signal

User configurable

Analogue filtering

Digital filtering

Calibration

Optional Programming Kit