Hi,
I am trying to set up a CAN bus monitor with the USB-8473 product.
I can not see anything. I have configured a microcontroller-based board as a node on the CAN bus. I need to match the timing requirements for bot the uC and the NI USB-8473 board.
I don't understand the difference between baud rate and bit rate.
I have set my micrcontroller to the following bit rate settings:
CAN Bus Bit Rate: 125 kbps
CAN Bus Clock : 40Mhz
BRP = 32 (BRPreg=31)
TSEG1 = 4
TSEG2 = 3
BT = 10
Triple Sample Mode
I program it to continually send a message on the CAN bus from Mailbox 0, with a certain ID, etc.
In NI's MAX (Measurement and Automation Explorer) I set up a bus monitor as follows:
In My System ->Devices and Interfaces -> NI-CAN Devices -> USB-8473 ->CAN0
In properties I choose "Edit the Segments of the Bit Timing Register"
I select:
BRP+1 = 6
SJW+1 = 1
TSEG+1=5
TSEG2+1=4
Triple Sample Mode
This results in a Sample Point of 60%
I have added a 150 ohm termination resistor on the CAN bus wire.
All this results in 133.33 kBaud.
So, what am I doing wrong? I can't see anything on the CAN Bus Monitor.
What is the difference between kBaud and kbps.
How do I set the timings of the two nodes the same?
Thanks,
Rick
