API SPI_ATTN does not toggle while receiving packages


Greet all XBee community. I’m try to send packages from coordinator to router and both of them are in API mode. Coordinator is connected to PC and sending packages through XTCU software while router is connected to MUC. First, I send a package and the data out is appear on DOUT pin of the router instead of MISO pin. So I connect DOUT pin to GND of MUC in order to force the router to use only SPI pin.I try to send packages again but SPI_ATTN pin doesn’t change to low level and no data is coming out of MISO pin. Here some my configuration.

Coordinator : API Mode connected to PC.
Router : API Mode connected to MUC and DOUT pin is
connected to GND

The S2B modules don’t support SPI mode. You need to use the S2C for that function.