CAN/TTCAN simulator system based on educational DSP hardware kits

Simulation is useful on designing industrial communication systems and also a powerful teaching support tool. This work presents a CAN simulator system built on educational DSP hardware kits. Its design allows the study of network temporal behavior and its performance under a message workload. This is done by checking on the bus hardware several variable values for different bus parameter configurations. A CAN extension for time-triggered communication, the TTCAN bus, can also be simulated through a firmware upload on the simulator. The bus message set, the individual message specification and its timing requirements are downloaded to the hardware simulator through a PC connection. A software tool running on this PC records all timing information collected directly from the bus, on a bit time basis. This information can be used to evaluate specific message scheduling policies and network configurations for a message set. Results validation compares simulation values with those computed from an analytical model. Examples of simulations considering different bus window assignments and their effects over the message set schedulability are presented and discussed.