RS232C-based plug & play multiple master serial communication

The circuit and topology of RS232C interface are investigated to reveal the mechanism of multiple callings from terminals, and the errors from a collision are studied. The calling strategy and frame formats for data communication, registering and quitting are designed to listen and identify a collision out of two or more calling occurred simultaneously. It shows that the communication strategy of Multiple Callings from terminals to central computer with RS232C protocol is feasible and reliable.