Why Doesn't MD4 Support 1000kbps CAN?

Nithin V 5 years ago in IQANdesign updated by Gustav Widén (System support) 5 years ago 7

Why is the 1000kbps setting not available in IQANdesign for MD4-7 display modules? Is this a limitation of the hardware? Most modern CAN transceivers and controllers should support this baudrate, so I am confused why it is not available.

It does when defined as a Generic CAN bus.  J1939 on all modules only supports 250k / 500k.  This is a software limitation becuase SAE has not specified anything beyond 500k.

This is a screenshot from IQANdesign 6 with one MD4-7 as a master module and generic CAN at 1000k. At least for me, 1000k CAN speeds are not supported, regardless of the bus protocol.

what CAN bus is it connected to?

Regardless of which bus I use, I get the same error when I set the generic bus to 1000k.

Interesting.  I just noticed this too.  It appears it is also not available in IQAN 5.04.


It is a limitation due to the hardware design of the MD4. We limited the max speed to 500 kbps because of the capacitors we use on the MD4 CAN buses. 

On the MC4x, the design is slightly different, enabling higher bus speeds.