Ni 9861 -> stm32f042 via iso1050

[alex1457]

There is a Mk stm32f042 and a board from National Instruments (NI).

They must communicate through an ISO1050 transceiver. The problem is that the message from MK to NI reaches, but not in the opposite direction.

The photo shows the captured signals. on top there are two signals from ISO1050 feet - CanH and CanL.

Below - signals from the legs that go to / from the MK.

When the message comes from the NI board, the signal on CanH and CanL is not what it should be? What could be the problem?

Signal from NI9861 to stm via iso1050

 

Signal from STM32 to NI9861 via iso9861