MODEL 221 DIGITAL FREQUENCY TO VOLTAGE CONVERTER

Features

• Fast response
  
• Engineering unit display
  
• Input isolation to 1000 V
  
• Digital and analog outputs

Description

The Model 221 consists of a 19" wide x 5" high x 14" deep rack adaptor, with rack-mounting ears removable for benchtop use. Operation of the unit is over a wide band of frequencies from 0.5Hz to 76,800Hz. The output is in both 16-bit digital and analog voltage format.

Specifications

Input: 0.025V peak to 100V peak

Input isolation: Transformer isolated to 1000VRMS, or direct coupled

Common mode rejection: 2.5VRMS DC to 1kHz will not trigger the unit

Input comparator: Front panel adjustable trigger threshold from 0.02V to 10V

Frequency ranges: Front panel switch selects one of eight fullscale ranges: 600Hz, 1200Hz, 2400Hz, 4800Hz, 9600Hz, 19200Hz, 38400Hz, or 76800Hz

Low-input cutoff: Input signal below 0.25% will cause outputs to go to zero and a no-input indication to light

Pulse output: Logic level (0-5V) output at the input frequency

	Frequency	16-bit unsigned binary number (0 to 65535) representing percentage of fullscale frequency
	Selected range	Three bits indicate selected range
Digital outputs:	No input	One bit indicates no input signal
	Data valid	One bit unasserted during updates
	Data enable strobe input	One bit strobes internal 16-bit data latch

Analog output: Jumper selectable 0-5VDC or 0-10VDC fullscale output, with front panel trimpots to adjust span and zero

Test mode: Self-test mode allows output to be set to 0% or 100% fullscale to adjust front panel span and zero trimpots accurately

Display controls: Range pushbutton cycles through eight fullscale ranges; Decimal Point pushbutton shifts decimal point in display; 4-digit K-Factor thumbswitch selects multiplication constant to scale display in engineering units, such as percent full scale, frequency, RPM, gallons per second, etc.

Calibration: Internal crystal oscillator provides 50% fullscale calibration frequencies on remote command or by front panel switch

Output accuracy: ±0.05% of fullscale reading

Transient response: 4/f (4 periods of input signal) max (2 to 3 typical) up to 9600 Hz range; Higher ranges are 8 periods, 16 periods, and 32 periods max

Display update rate: Switch settable from 4 seconds per update to 1/4 second per update

Output noise: 2mV RMS max, DC to 100kHz

View our Price List