Communication systems play a major role in our daily life; people use cell phones, satellites, internet, and data transmission. All these applications are used in an environment exposed to noise sources; also data might be transmitted for long distances. These effects could cause changes in data values causing data corruption and loss. This led to the introduction of channel coding to detect and correct transmitted data. The channel coding is the adding of redundancy bits to assure that errors can be detected and corrected successfully. The channel coding is divided into two main types Block codes and Convolution codes. Simulink modeling of convolutional encoders. The configuration covered modeling of configurable rate convolutional encoder with Viterbi decoder from a mother code rate of ½ to1/3 and 2/3 with constraint length 7. The modeling is done by changing rates of convolutional encoder and error of binary symmetric channel using simulink blocks.