Name: Custom Serial Communications

The customer wanted a Variable Frequency Drive (VFD) that would run using their proprietary serial communications and supplied in the United States.

Overview: Using circulating heated air, an industrial convection oven bakes in a shorter time period. The rate of hot air circulation must be tuned based on the product being baked. An Adjustable Frequency Drive (AFD) is used to vary the fan speed of an induction motor. The hot air circulation is controlled by the VFD that is controlled by the oven recipes.

Application benefit: By establishing a Variable Frequency Drive supplier in the US, business communications would be improved, supply and delivery times shortened, and production costs lowered.

The customer's product: The customer's product is an industrial convection oven that shortens baking time by increasing the hot airflow rate.

The customer's present solution: Currently, to set the airflow rate, the customer uses an expensive European VFD.

The customer's request was to use a lower-cost, US-supplied VFD; however, the customer did not have the details of the serial communications protocol.

The customer sent the convection oven's electronics and existing VFD to KB's engineering lab, enabling them to monitor the serial protocol and use reverse engineering to decode the serial messages.

KB's capabilities for solving the problem: It's the KBVF Adjustable Frequency Drive series. This series incorporates the powerful, second-generation, micro-controller that is programmable for custom OEM applications. The digital interface DIVF provides isolation and signal conditioning for the serial communications. KB's engineering staff has a reputation of working directly with customer applications to reach satisfactory solutions.

The KB solution: The objective was to integrate the customer's proprietary serial communications into the KBVF-24D. The customer's proprietary serial communications were reverse engineered and the data byte patterns and serial communications message bytes sorted. The KBVF serial communications were customized to create and recognize these same messages. The new oven controller is able to send speed reference and start/stop command messages to the KBVF-24D while monitoring the Drive's operating status.

The results: Using the KBVF-24D with custom DIVF serial communications software based on Modbus, the customer has an improved oven controller that integrates the KBVF-24D, the DIVF, and the customer's controls.

The strategic advantage: The customer got exactly what he wanted - no more, no less - and he has a new, lower-cost oven controller providing increased cabinet space, shortened delivery cycle, lowered costs, improved communication with local suppliers, and a strong competitive edge.

A Win-Win solution for both the customer and KB.