Laboratory Scale to PLC

In this example, we’ll connect a Velocio PLC to an Adam Equipment CPWplus75 lab scale.  Find more about Adam Equipment on their website:



The Scale to PLC connection involves 3 wires.

  1. PLC ground to Scale ground
  2. PLC Tx to Scale Rx
  3. PLC Rx to Scale Tx





The following PLC program implements 5 of the industrial scale’s functions

  • Tare/Zero – which sets the zero weight, so that you can measure things inside a container and not the container itself.
  • Hold – holds the last value for a period of time
  • Read Net Weight
  • Read Gross Weight
  • Read Tare Weight

Download the Program: