CANJaguar

[Kodiak]

Originally Posted by dyanoshak

Bryscus is correct:



It is in fact 20' total, not the maximum between each Jaguar. The Jaguars aren't switches or repeaters, the left and right CAN ports are wired directly to each other on the Jaguar circuit board.

This 20' limitation does have to do with the CAN driver:

When all the Jaguars are responding at the same time to broadcast messages they drive the bus slightly higher than a single Jag would. It takes longer for the bus to return to 'zero' and therefor some Jaguars may not read the bit correctly if the bit hasn't had time to settle.

The time from high to low depends on the termination resistance as well. This is the reason why we also specify a 100 ohm termination resistor. It helps snap the bus back to zero quickly so there aren't any bit timing errors.

We found that 20' of cable, 100 ohm termination resistors, and ~16 Jags on a bus is a good limit for reliable operation. It may be possible to get more Jags, but the cable lengths will have to be shorter.

-David

Awesome, great information! thanks for the clarification.