The invention discloses a redundant on-site
bus I / O control device comprising a control mainboard, a display control panel, a power supply terminal, a switching value incoming
signal terminal, a switching value output
signal terminal and communication terminals. The control mainboard comprises a central processor, a storage, a power supply interface, an input interface, an output interface, two DP slave
station controllers, two optoelectronic isolation circuits and two transmit-receive circuits. The display mainboard comprises a button set, a display screen and an indicating lamp set. In the invention, two DP slave
station interfaces are respectively controlled by the DP slave
station controllers corresponding to the DP slave station interfaces, and can respectively carry out
complete data communication with a main station. When the control device is electrified, a power indication lamp shows the
electrification. Through two indicating lamps, states of two DP networks are displayed. Through a display screen, measurement and configuration data are displayed. The communication terminals allows two
modes which are a pluggable terminal and a DB9 socket to be employed. The wiring mode is selectable. The redundant on-site
bus I / O control device of the invention is simple in structure, low in cost, high in communication rate and is reliable and stable. Usage of cables is greatly reduced.