Introduction To Serial Communication - WEG CFW100 User Manual

Introduction to Serial Communication

1 INTRODUCTION TO SERIAL COMMUNICATION
In a serial interface the data bits are sent sequentially through a communication channel or bus. Several
technologies use the serial communication for data transfer, including the RS232 and RS485 interfaces.
The directions that specify the RS232 and RS485 standards, however, do neither specify the character format,
nor its sequence for the data transmission and reception. Therefore, besides the interface, it is also necessary to
identify the protocol used for the communication. Among the several existent protocols, one used a lot in the
industry is the Modbus RTU protocol.
In the sequence the characteristics of the RS485 and USB serial interfaces available for the product will be
presented, as well as the Modbus RTU protocol for the use of this interface.
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.ctiautomation.net - Email: info@ctiautomation.net