The I/O modules of the 1785-BCM form a dual Genius control network, which monitors the system through a double-layer redundant Ethernet (non-ring type) using two servers (with priority) and one operator station. The whole system is divided into 33 remote I/O stations, DI928 points, DO480 points, AI56 points, AO40 points, and nearly 800 points of the fire control system fire valve status signals through the OPC mode to the series 90-30 PLC for chain control. Using CIMPLICITY HMI upper monitoring software to achieve dual-server data synchronization and scripting operation dialogue box, and incorporate priority levels.

After the explosion of the 1785-BCM control system, an Allen Bradley Series 90-30 dual machine hot standby PLC is now used to implement the anti-surge function and unit interlock protection of the air compressor, and a Digital Japan GP-470 touch screen is used to implement the monitoring and operating functions. Now not only the operation is intuitive and convenient, the reason for stopping is clear, but also the design of anti-surge system of air compressor is more perfect, and the operation of the unit is more stable.

1785-BCM is mainly used for data acquisition, control and regulation in the integrated automation system of hydropower station, which plays a pivotal role in the normal operation of the power station, and how to achieve data communication between PLC and the host computer is also crucial. This paper is precisely for the series 90-30 PLC only need to communicate with the industrial control machine occasions, a detailed comparison of the series 90-30 PLC four serial communication protocols, and focuses on the PLC and the industrial control machine through the power supply module on the 485 serial port using the SNP protocol to communicate the specific implementation of the process and should pay attention to the matters.