Abstract
RS-232 only for a short distance communication, introduced for the
10 meters. And the anti-interference ability is not very ideal.
Compared with RS-232 and RS-485 has a lot of advantages, first of all,
the communication distance is far more than the former, usually can
be hundreds of meters or even kilometers above, but also can realize
multi-point communication mode, so as to establish a small LAN, so
more use value. And it uses the differential mode signal transmission
mode, and a ground level relationship is not, so its
anti-interference ability is far stronger than the former stract.
This paper introduces how to design a RS-232 transfer RS-485 the
level conversion circuit, based on RS485 implementation of the PC
serial communication between SCM and PC control system through the
RS485 and RS232 signal conversion circuit, PC machine according to
the machine address of uninterrupted collected under the crew of the
data, after treatment, the control signal is transmitted to the next
machine, thereby realizing between PC and single-chip microcomputer
multichannel remote data collection and control.
Keywords: RS-232;RS485; Single chip microcomputer; Serial communication