Converting an Analog Signal to a Modbus Output

All industries are interested in improving their processes, whether in the area of quality, safety or cost reduction. The use of sensors to continually measure and monitor the process is growing as plant managers see the benefits of keeping the process at the right temperatures, scraping less product due to break downs and using the least amount of energy possible. Each sensor has a specific function and each are equally important to achieve the overall goal of the perfect process.

NK Technologies makes a large selection of sensors to measure electrical parameters, including current, voltage and power. Collecting the output of each sensor into a programmable logic controller or other system controller can be expensive with a large number of analog signals and time consuming to program so the controller knows exactly what it is being told. We now offer a small device which converts these analog signals into an industry standard (Modbus RTU) digital format.

ADC Series Digital Converters

We are proud to introduce the new ADC product group. Up to eight 4-20mA output signals can be connected to one converter, in three combinations of signal types and powered from your choice of 120 or 240 VAC. If your sensors use a two-wire design with 24 VDC connected in series with the sensor output, NK Technologies offers a model which will power and convert up to eight inputs. Many 4-20mA sensors use a separate power supply in a four-wire design (two for power input, and two for signal output). The ADC converter can be supplied with up to eight four-wire inputs, and also a combination of four two-wire and four four-wire inputs. Each input signal can be read across the Modbus network individually or all together. The digital output is scaled to represent 0 - 100% of the sensor range. As an example, a sensor producing 20mA with 100 amps through the window will be seen digitally as 100% with the same 100 amps being used. Each group of inputs will be assigned one Modbus address.