Distribution Controller Design Based On CAN Bus

The CAN bus distribution controller is for a certain type space vehicletelemetry system distribution requirements, specially designed for the arrow on thetelemetry system for the arrow on the equipment with3power supply branch(collected branch, transmission branch, radio branch) and unified power branchdistribution control. In accordance with the requirements of the overall technicalindicators, the power distribution controller CAN not only realize manualdistribution and CAN bus automatic distribution function, and CAN be collected6analog power distribution information,2road state information through the bus sentto the arrow on the master node.Distribution controller according to the different circuit function, CAN bedivided into the power distribution control circuit, the main processing circuit, CANbus communication circuit and relay control circuit, sampling circuit, power supplyand filter circuit, etc. Power distribution control circuit is mainly composed of relaytopology and arc suppression circuit, is the realization of the core module ofdistribution function of controller. It connects the arrows last power source and thetelemetry system, electrical equipment on the equivalent of a multi-channel remotecontrol switch, the implementation of relay control circuit sends distributioncommand manually or automatically. Main processing circuit connection each othereach function module, the key is to realize the bus automatic control, with the buscommunication circuit to realize the distribution instructions, sending and receivingdata. Relay control circuit is responsible for distribution command manually orresolve the main processing circuit of automatic power distribution commands sentto the power control circuit. Acquisition circuit is used to realize8-way distributionparameter measurement, AD conversion, and stores the result in the main circuit ofCPLD device. Their power and filter circuit is a converted to the demand ofdistribution controller function module voltage specification and improve powersupply quality filter processing.Software part used to implement the specific function of distribution controller,by the initialization function, main function, CAN bus transceiver function,distribution of the automatic control function, etc. Distribution controller is powered on, the initialization function complete microcontroller tube feet, the system clock,sending and receiving mailboxes, timer and interrupt initialization Settings.Detected in the bus, the program into the interrupt call reception function receivesthe message, by IF2ARB2register information, distinguish the framesynchronization, power distribution instructions, such as data request message type.If it is a frame synchronization message, control circuit of AD transform. Ifdistribution instruction, the main program will power distribution automatic controlfunctions, to execute commands corresponding distribution, and return to performmessage. When data is received after the request message, the main program readsthe data cached in CPLD of transformation, through the bus sent function to themaster node.Finally, Paper introduces the test method of CAN bus distribution controllerand environmental testing requirements, after a series of environment test, CAN busdistribution controller by experiment examination, this model in the telemetrysystem design requirements.