Keeping our Fingers on the Pulse!

Recently we have been working hard to update the T24 pulse acquisition module. Our purpose with this update was to ease usability with sensors and improve upon the battery life when used as a counter.

Our initial brief was to look at the types of sensors that would generate a pulse output. The majority of these sensors seemed to have a 10 V minimum supply. They also tend to be open collector outputs (both npn or pnp). Another common use of the pulse module is to measure pulses from a reed switch and these switches don’t need the power supply to be anything more than the battery voltage.

One of the biggest improvements we have made is to improve the counter modes. The count mode is now interrupt driven and does not need the excitation to be on at all.

To complete our update we added some extra measurement modes. We have retained all of them from the previous module (frequency, count, rpm, interval) and added some extras:

  • Quadrature. We have added a second input line to the board and we now accept quadrature inputs.
  • Digital State. This mode has been designed to deliver the digital state of the input pin. The value is sent immediately on change and at the configured transmit interval. This is ideal for button press applications where occasional state change is sent to a controller.
  • Mark (Space). The input is now able to report the mark space ration of the incoming signal.

To meet these challenges in sensor types we have made all these settings configurable from within our T24 Toolkit without the need for any external components.

Configuration is simple, just select:

  • The type of measurement you need
  • Excitation – Choose between Off, 3, 5 or 12 Volts DC.
  • Pull Resistor – Choose to provide an on-board pull up or pull down (56 kΩ).

Then simply start using it.

For further details, advise and support please contact us at


This article was written by Dr. Clive Vallance, Senior Electronics Engineer, Mantracourt Electronics Ltd