Performance Evaluation of the Acquisition Cycle for an Original Modbus Extension IIoT Gateway Based on Sitara AM335x Processor

Abstract-Although Modbus is a widely used and easy-toimplement protocol, it has its limitations. Specifically, it does not include any specification about time variables, making it incomplete. To address this issue, the Modbus Extension was proposed. This extension introduces a time variable, but requires a Base Station Gateway (BSG) to do so. The interval time is determined by the structure of the acquisition cycle (AC), which will be implemented at the BSG level. In this paper, we present a solution for implementing the AC using the PRU (Programmable Real-Time Unit) core of the Sitara AM335x from Texas Instruments. With this approach, we achieved a speed of 12 Mb/s and a payload data channel usage percentage of 53.3 %. Additionally, we evaluated the performance of the acquisition cycle in the context of an IIoT gateway developed around the AM335x processor.