Integration MATLAB and S7-300 PLC System; Case study in Bottle Detecting : This paper describes an implementation of using camera to capture image of bottle on conveyor belt. The image analysis will be done in order to determine a density of number of bottles (DNB) instead of using sensor or limit switch which activate when bottles arrived to detecting point of the sensor. The data from the image processing to be used in conjunction with the drive control system in order to adjust the belt speed in accordance with the amount of bottles in assigned zone on the conveyor. The image analysis will be done by MATLAB to obtain information on the number of bottles in the specific area. The data from MATLAB will be sent via OPC to S7-300 PLC for the motor speed control system. The experiment result shows that the system can exchange information and can actually work together.