Eliminating Modbus as a networking protocol would mean eliminating a legacy of innumerable Modbus standard products. Because it is an open specification, thousands of companies have standardized on it. In fact, Modbus is the most common protocol in the world.
According to HMS Industrial Networks' Development Manager Jorgen Palmhager, "If you take the U.S., European, and Japanese industrial markets together, Modbus is a preferred industry standard for serial communications. Even in the U.S. alone, over 50% of the market is using it as a low speed communication link."
Many of the products standardized on Modbus don't really need to transmit or receive tremendous amounts of data. In fact, it is their relative simplicity that makes redesign of these products a money-losing proposition. They work well, but in today's networked world designers just need to get with a network, as opposed to the simple serial communication they adopted Modbus for in the first place.
The range of such products is immense—from micro PLC's, scales, printers, operator panels, drives, and micro drives, to text displays, HMI's, sensors, instruments, motion control devices, barcode readers, and RF identification systems.
The HMS AnyBus Communicator connects industrial devices via an RS-232/422/485 interface to all major industrial Fieldbus networks. No hardware or software modification—nor extensive engineering work—is needed, according to Palmhager. "This new protocol converter enables instant connectivity to PROFIBUS, DeviceNet, Ethernet CANopen, ControlNet, LonWorks, and Modbus Plus."
The AnyBus Communicator is a small (approx. 4.75×3×1 inch), standalone gateway that is DIN rail mountable. It is powered by an industrial 24V power supply and consumes typically only 100mA. It targets all those products that provide only a serial interface and no direct network connection. Using the new AnyBus Communicator, even these components are said to be easily integrated into industrial networks.
On the Fieldbus side, the AnyBus Communicator always acts as a slave. On the serial side, it acts as a Modbus master or slave. It supports all baud rates from 1,200 baud up to 38.4 kbaud. In RS-485/422 mode, the AnyBus Communicator supports multi-drop configurations to connect multiple serial devices to the selected Fieldbus.
AnyBus Communicator is fully configurable through a user-friendly Windows configurator. It hooks up to a PC through the configuration port and configures the fieldbus network properties as well as the serial sub-network. The same port can also be used for online diagnostics and monitoring.
A manufacturer offering the Communicator to its customers typically would have predefined configurations done by its application engineers, according to Palmhager. "If they are getting all the right information mapped to the Fieldbus, then they can just hand this configuration file to their customer. Their customer would then download it and run with it. Thus the end customer may not have to do any configuration."
Manufacturers can even sell the Communicator as an accessory to those end users who need to be connected to a network without going through the development effort of designing in an embedded network-translating device.
For more information about Anybus Communicator from HMS Industrial Networks: Enter 533