Digital to Analog Converter

The Motion Sensors (MSI) PCA121S Digital to Analog Converter is a convenient and low cost device that will provide current and/or voltage based analog output from pulsed signals when these are needed to drive plotters, recorders, printers, and other data acquisition equipment.

Its intended use is with sensors, preamplifiers, and other devices that produce digital, pulsed output when analog output is also desired.

The PCA121S can be used, for example, with our Digi-Pulse (DP), Hall Effect (HE), and Magnetoresistive (MR) sensors, as well as our PA1001A and PA2001 series of preamplifiers. The PCA121S can also be used with our Intrinsically Safe products when it is mounted on the "safe" side of the barrier.

Installation Drawing

Input Power

  • Voltage: 8 to 30 VDC
  • Reverse polarity protected

Pulse Input

  • Frequency range: 0 to 12.8 KHz
  • Pulse type: 0 to 5 TTL/CMOS (other types of pulse inputs also available; contact factory for details)
  • Max. distance from sensor to preamp: 100'

Current Output

  • Accuracy: +/- 0.05% of full-scale +/- 200 PPM
  • Available range: 4-20 mA
  • Output suitable for driving, floating or grounding loads
  • Maximum loop impedance: 500 ohms
  • Response time: 3 seconds for 10% to 90%

Voltage Output

  • Accuracy: +/- 0.05% of full-scale +/- 200 PPM
  • Available range: 0 to 5 VDC or 0 to 10 VDC, user selectable
  • Impedance: <10 ohms
  • Response time: 3 seconds for 10% to 90%

Temperature Range

  • Operating: -40°F to +185°F
    (-40°C to +85°C)
  • Storage: -40°F to +302°F
    (-40°C to +150°C)

Physical Dimensions

  • 2.58" MAX x 1.5" MAX x 0.41" MAX


  • Unit is intended for mounting in a conduit box. Custom configuration for other housings available. Enclosure is not required but is recommended to protect unit from moisture, dirt, etc.

Terminal Connections and Type

  • Input Pulse and Power: (Terminal Block 2) Pulse (+): terminal 1
  • Common (-): terminal 2
  • Power (+): terminal 3
  • Analog output: (Terminal Block 1) Voltage (+): terminal 1
  • Common (-): terminal 2
  • 4 to 20 mA (+): terminal 3
  • Type
    Screw-down (optional Phoenix type with mating connector also available)


  • CE compliant to EMC Directive 2004/108/EC for use in residential, commercial, light industrial and heavy industrial environments


  • Unconditional one (1) year warranty if used within specifications
ATEX & IECEx Certified: Custom & Standard Speed Sensors for Intrinsically Safe applications (also approved by CSA w/NRTL/C)