Partie interactive du site pédagogique ELECINF344/ELECINF381 de Télécom ParisTech (occurrence 2011).


TSV Safe Express: Timing issues.

Today Alexis delivered us the whole set of the train light circuit. Initially we tried to add another light card to our current testing configuration. We managed to get 2 light cards configured , so up to this point the central station has been able to control 2 light cards, the train and an ethernet connection  in total.

Currently we are working on stabilizing the  NMRAnet CAN bus protocol. We encountered problems  of what we think mainly concern,  a difference between the CAN bus bandwidth  and the processing bandwidth of the central station. For example, as we observed, during programming the events of a node,  within an environment of multiple CAN packets exhange, the central station missed acknowledgement frames sent by the node after  the configuration file. This prevented the central station from successfully programming a node. After inserting a delay between sending the data of the configuration file and the ACK we observed that the node got successfully programmed. This led us to assume a mismatch in processing and CAN bus bandwidth.

In order to face these kind of problems which have appeared, we will adjust the CAN bus bandwidth, use one buffer for event processing and another one for network-management purposes, and additionally install event filters on the fly accordingly for each node.


Sur le même sujet :

  1. TSV Safe Express: Day’s work.
  2. TSV Safe Express: DCC Signals and Ethernet
  3. TSV Safe Express: NMRAnet CAN bus.
  4. TSV Safe Express: à partir de carte TP à la carte réelle
  5. TSV Safe Express:the day of SPI and Led Driver

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