I have setup two chanels to send data from PC to micrcontroller. Both of them were working initially. Now one of the chanel does not work. WHen I dont send any data, Impedence between Can-H and Can-L is 120 Ohm on both chanels. WHen I send data, impedence of of the faulty chanel goes several order higher and status of CAN bus becomes passive.

My questions are What does it mean "CAN Bus is Passive" Why impedence changes when I send data?

I am using HI 3110 to interface can bus to micrcontroller.

I have setup two chanels to send data from PC to micrcontroller. Both of them were working initially. Now one of the chanel does not work. WHen I dont send any data, Impedence between Can-H and Can-L is 120 Ohm on both chanels. WHen I send data, impedence of of the faulty chanel goes several order higher and status of CAN bus becomes passive.

My questions are

• What does it mean "CAN Bus is Passive"?
• Why does the impedence change when I send data?

I am using HI 3110 to interface can bus to micrcontroller.