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CANNY logic forum → CANNY 7 → CAN - Reading several packets at once
Hello
I need to ready several CAN packets and process the results. In the documentation, the example is reading only one packet.
What would be the best way of doing the flow in Cannylogic to read several packets at once?
Thank you for your help!
Maybe attached diagram will be helpful. If not, please provide more details.
4ch.cfd 3.53 kb, 307 downloads since 2019-12-05
Hello
Thank you, so 16 max.
Stephane.
so 16 max.
Only if you will use filtering mode.
If the filtering mode is not switched on, you will receive every message (adjusted for controller performance).
Hello
What do you mean?
Can I have many times a check on CAN RX IDL?
Then how this work? The Micro Controller receives all packets in a queue. How are they parsed? One packet per loop?
Stephane
You must check 'CAN Data Received' register.
If it =1 then CAN message reading registers set contain actual last received message.
You can proceed one message per diagram loop.
The loop time depends of diagram size, controller perfomance and driver's load.
For CANNY 7 the diagram loop time is from <1 ms for small diagrams to ~10 ms on biggest.
You can get last loop time in milliseconds in spetial register.
Please visit https://wiki.cannylogic.com for more information.
Hello
OK. So considering a CAN Bus at 500kbps, the loop time will be too slow so we will overflow? This is why it is far better to use the filters?
Steph
Better considering CAN utilization rate, not baudrate.
Anyway, you have CAN Overflow register for diagnostic.
Internal 16-messages deep CAN RX buffer may help in some cases.
Also filters can be changed on the fly.
What exactly are you going to do with the controller if you are going to?
Can you provide details of your task?
Hello
It will be connected to the CAN BUS of a car (so there are tons of packets) to create a security module.
Steph
CANNY are widely used in car security area. Maybe you should try it. You may not need as much different IDs to listen as it seems.
Yes so back to the point it is required to use the Filtering capability.
Steph.
CANNY logic forum → CANNY 7 → CAN - Reading several packets at once