The customer was making a product that had 4x 4-20mA analogue inputs and 10 digital outputs (8x zero-volt and 2x driven outputs). They were controlling this with a panel containing a PLC, HMI, PSU and a dozen wiring terminals mounted on DIN rail. They approached HDL looking for methods of cost reduction.
Based on an agreed order quantity, HDL designed and had manufactured a PCB which included all their required inputs and outputs, and additionally included a PSU and modbus out to communicate with the HMI. The inputs were designed to work directly with the 4-20mA sensors and driven outputs so that all inputs and outputs could screw directly to the board – no additional terminals or wiring was required. HDL then added some additional digital inputs and sell the board as a product for others to use.