The real time verification when replacing DH PLUS with DeviceNet for tire conveyor system

To replace the existing DH PLUS (data high-way plus) control network with DeviceNet control network for a tire conveyor system, we compared and analyzed communication characteristics due to variation of factors, such as transmission speed and transmission cycle, using a demonstration system. For verifying real time communication in the network-based control, we determined the architecture of the DeviceNet network control system and applied it to the system. The experimental system consists of PLC processor, scanner modules, proximity sensors, motor, two kinds of network cable and so on. 57.6 kbps and 230.4 kbps were used for DH PLUS network and 125 kbps and 500 kbps are used for DeviceNet network in communication rate. In case of DH PLUS network, when the transmission cycle was more than 2 s, transmission error hardly occurred, however, when the transmission cycle was less than 1 s, more than 15% of the transmission data was lost. In the case of DeviceNet network, when the transmission cycle was more than 0.2 s, transmission error hardly occurred, however, when the transmission cycle was less than 0.15 s, a little transmission data was lost. As a result of this experiment, system realization of DeviceNet control network was proved to be ten times better than that of DH PLUS control network, when the transmission cycle was short. The results can be effectively utilized when CANBUS-based DeviceNet network is implemented on the practical tire conveyor system.