A white paper, titled “Using Modbus for process control and automation,” is available for download from Moore Industries.
The non-commercial white paper, written by Vince Marchant, a senior application engineer at Moore Industries, describes how Modbus works, and how it can be used in new and legacy process control and automation systems.
The white paper explains that Modbus is the most popular industrial protocol being used today, for good reasons. It is simple, inexpensive, universal and easy to use. Even though Modbus has been around since the past century, nearly 30 years, almost all major industrial instrumentation and automation equipment vendors continue to support it in new products.
Although new analyzers, flowmeters and PLCs may have a wireless, Ethernet or fieldbus interface, Modbus is still the protocol that most vendors choose to implement in new and old devices.
The white paper notes that another advantage of Modbus is that it can run over virtually all communication media, including twisted pair wires, wireless, fiber optics, Ethernet, telephone modems, cell phones and microwave. This means that a Modbus connection can be established in a new or existing plant fairly easily. In fact, one growing application for Modbus is providing digital communications in older plants, using existing twisted pair wiring.