In the field of automatic control, using a microprocessor application system to monitor and control an automatic system is quite common and its usage rate are still increasing. Microprocessor can support complex processes scheduling, and accurately control on time and position. However, even a highly professional programmer still needs a lot of time to maintain the control programs running on this kind of control system. The advent of the programmable logic controller (PLC), which consists of CPU, data memory, digital and analog I/O port, and power module provides an alternative for designing an automatic system. It¡¦s used in the field of industrial control widely. Compared to the microprocessor-based control systems, the PLC-based control systems have the advantage of providing a development environment for easily programming and maintaining. However, the high cost, poor signal processing ability, and the restriction on the function of device are the major drawbacks of PLC. To solve the problems described above, this paper taking the advantages from the PLC-based microprocessor-based control systems proposes a PLC-like development environment for creating a microprocessor- based control system. To accomplish this goal, according to the object- oriented concept, this paper classified the device in a microprocessor into four categories, GPIO, ADC, Timer and Serial-com. And also provides an interface window for users to set and access device register. In addition, this paper provides a set of user customizable task module tools to easily establish a PLC-like based system. Then system developers can write a program via a simple event-table-driven way, and build up the operating procedures according to the approach of sequential multitasking. Our research result make the building of microprocessor-based system can be clearly divided in to three stages, microprocessor manufacturer, advance user, and generally user which not only makes the development of product easier and faster but also meets the time-to-market demands. In the future, some advanced technologies can be added into this automatic controller development tools to make it smarter and more automatic. For example, the environment can support the developed technology for multi-thread and multi-core microprocessor to analysis and establish Instruction trace, and adjust the load balancing automatically. Or it can integrate the graphical programming allows users to program simpler and more intuitive.

In the field of the industrial automatic control, both MCU (Micro Control Unit) and PLC (Programmable Logic Controller) are widely being used in DCS (Distributed Control System). Since MCU can provide complex process scheduling, accurate timing control and PLC has the advantages of easy programming and maintaining. However, the control programs of the MCU are hard to design and maintain. Identically, the poor signal processing ability, high cost and the restrictive functions are the major defects of PLC. In order to solve the drawbacks described above in MCU and PLC, we provide a PLC-like interface for users to access the devices and set the registers of MCU. Likewise, designers can develop the control program via Event-table-driven modules. On the other hand, our main goal of DCS is to quickly construct the distributed N level network topology based on Modbus protocol, which is efficient and reliable. Therefore, we bring up a data collection method and Slave-to-Slave strategy so as to distribute the master loading, reduce the package transmission times and improve the real-time latency. In conclusion, our research results not only congregate the benefits of MCU and PLC but provide an environment to quickly construct and conveniently monitor DCS, which meets the time-to-market demands.