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Dial “M” for Modbus!

by Glenn Johnson

We here at Applied Motion Products are excited to announce the newest addition to our ever-expanding list of communication options: Modbus RTU (check out all of our downloadable app notes here).

Modbus RTU operates on a serial link, and is optimized for use on RS-485. It operates on the principle of registers, which can be used to monitor the drive’s behavior, send data to and from the drive, and execute commands. It is uniquely suited to PLC applications since PLCs use a similar memory model by design. As such the Modbus RTU protocol is typically already integrated into most PLC and HMI platforms as a generic driver.

Now for the question of the day: Why is this important? I’m glad you asked! Modbus, with its simplicity and widespread acceptance by PLC and HMI platforms, brings a number of benefits to the table. Among them:

• By mapping SCL commands to Modbus opcodes, the machine designer has access to the full motion capabilities of our popular Q drives, which will offer far more sophisticated levels of control than is typically possible from PLC pulse motion output signals. See the product page on our website for details.

• It is possible to launch a stored Q program, further extending the performance capabilities when compared to a standard PLC step/direction control scheme.

• Sample projects and application notes are available on the website, which will allow the designer to quickly and effectively put the product to use with many different types of controllers.

• More models coming soon!

The new protocol will be available on all Q-enabled drives and can be configured with the ST Configurator™ software. For the initial phase of the release the following drives are currently available with the Modbus RTU option:






Please note that the Modbus option is implemented in firmware revision 1.06A, so your drive will need to have this revision or later loaded in order to take advantage of this exciting feature. If your drive has an older revision loaded, please contact our Applications Engineering department or online chat for upgrade options.

Be sure to check out the Product Page to follow the release and find detailed technical specifications and explanations. A number of application notes are also currently being developed which will help to demystify the integration process.

Modbus® is a registered trademark of Schneider Electric, licensed to the Modbus Organization, Inc.