Applied Motion RS-232 - Manual (Page 241)

241 920-0002 Rev. I
2/2013
Host Command Reference
Appendix B: Host Serial Communications
When a drive is operating in “host mode”, it means that a host device sends commands to the drive (or
drives) over a serial connection (or network) and the drive executes the incoming commands. Here are some
examples of typical host devices:
• A Windows-based PC running Applied Motion software
• An industrial PC running a custom-built or other proprietary software application
• A PLC with an ASCII module/serial port for sending text strings
• An HMI with a serial connection for sending text strings
The aim of this appendix is to describe the following aspects of operating an Applied Motion Products motor
drive in host mode.
• General structure of host serial communications.
• Hardware – wiring and connecting a host device to the serial ports of an Applied Motion drive. (Covered
in detail in Appendix C).
• COM Port Settings – UART settings and Bit Rate (Baud) settings.
• Communications Protocol
• Communication Details
• Communication Errors
General structure of host serial communications
Applied Motion’s host serial communications are based on the common ASCII character set transmitted
using standard UARTs over an RS-232 or RS-485 hardware interface.
The ASCII character set is used because it is common and well-understood, as well as easy to read. UART
(Universal Asynchronous Receiver Transmitter) serial transceivers are available on many types of equipment,
including most PCs, and provide a common form of serial communications interface. RS-232 and RS-485
hardware connections are commonly used with UARTs and also provide the easiest and most common form of
connectivity.
Hardware
Details on drive terminals and connectors for wiring each of the available hardware configurations are shown
in Appendix C. Below is an overview of the three available configurations.
RS-232: This is the easiest method for drive serial communications. Using an Applied Motion supplied
adapter/programming cable (one supplied with each Applied Motion drive) a single drive can be connected directly
to any PC with a standard 9-pin RS-232 serial port. Here are some RS-232 highlights:
• Easiest to use
• Configuration of choice for using Applied Motion software applications such as Q Programmer, Quick
Tuner and STAC6 Configurator
• Short Cable Lengths
• Serial cable provided with each Applied Motion drive
• Susceptible to EMI
RS-422 (4-wire RS-485): RS-422 was originally designed for high reliability communications in point-to-point
configurations. It usually requires a special adapter to work with a PC but is common on many types of controllers
such as PLCs and HMIs. Our implementation allows for multi-drop communications with a single master (serial
network). Here are some RS-422 highlights:
• Relatively easy to use
• NOT supported by Applied Motion software applications such as Quick Tuner or STAC6 Configurator. (Q