industrial PC with VC programming

 

 

XIONG Tianzhong1,2, YE Wenhua1, YANG Bin1,

MAO Donghui1, WANG Qiao1, HUANG Yanfei3

 

(1. College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics and Astronautics,

 

Nanjing 210016, China; 2. College of Electrical & Automatic Engineering, Sanjiang University,

 

Nanjing 210012, China; 3. Nanjing EUCH CNC Machine Tools Co., Ltd., Nanjing 211199, China)

 

 

Abstract: In order to realize the sequential control function similar to PLC in industrial PC(IPC), a VC programming method based on sequential function chart(SFC) was proposed. Taking a typical SFC as an example, a thread was started to simulate the PLC main scan cycle so as to have no effect on other HMI operations. The main scan cycle program includes the input mapping, the step transferring, the step outputting and the output mapping subprogram in sequence. The PLC timer was implemented with a new thread and the Sleep function. The main ladder program of Siemens S7300 PLC to realize this example SFC was proposed, by contrast, the step and the key code to implement it by VC was described in detail. All the code was programmed and debugged with VC++6.0 on PC, and the main scan cycle period was measured by the Windows CPU stamp counter. The experiment has proved that the proposed method can well accomplish the sequential control function with short cycle period and meet the industrial control requirement and worth to be applied properly.