Incoming data priority and Maximum data rates
Incoming data priority
RT Live has 3 “data sources”
- Data received from CAN port
- Data received from Serial port
- Data received from internal sensors
As the same data (eg. a temperature sensor) can come from any of the 3 data sources, the RT Live unit assigns then to have 3 different “priorities”:
- CAN data has the highest priority.
- Serial data has the second highest priority
- Internal sensors have the lowest priority
So for example if data for “Temperature 1” is received on the serial port, then will be logged in preference to “Temperature 1” data that is generated from an internal variable, and this data will be lost.
Maximum data rates
- Serial Data - Maximum data rate 115 Kbit per second
- CAN Data - Maximum data rate 1 Mbit per second (Practical limit is significantly lower than this, CAN buses are rarely run above 500kbit)
- Feeding writing to internal memory - Maximum data rate 5 Mbit per second
- GSM data upload rate - Maximum 240 kbit per second
- Internally generated data - Maximum rate 16 kbit
- maximum storage rate to internal memory 350kbit per second
So based on the above for an application, if the RT live unit is only connected to a serial data source, then assuming there is a good GSM signal, the unit will “keep up” and upload data to the server is almost real time.
However if the unit is connected to a CAN data source, raw CAN mode is being used, and the CAN bus is running at high loads then it maybe the case the GSM link will not “keep up” and data will be buffered internally.