LTC6810-1 iso-SPI Communication Problem


I have a probelm with isoSPI communication in LTC6810-1 Battery Monitoring IC. I have a proper communcation with the 1st IC using SPI, but the communication between this 1st Slave and 2nd one is through isoSPI, they are connected in series. Its not working. Please help in resolving this issue. 

Thank you with Kind Regards,

Anup Pravin1st Board with SPI.pdf2nd Slave Board with isoSPI.pdf