zedboard with readback capture through BSCANE2 primitive

Hello experts,
 
I try to build the readback capture design on the Zedbroad according to this tutorial:
https://www.xilinx.com/support/documentation/application_notes/xapp1230-configuration-readback-capture.pdf
 
But I met the error prompt during bitstream generation:

ERROR: [DRC 23-20] Rule violation (PDCN-2) connects_TDO - BSCAN_X0Y3: Must use the input pin TDO
 
I have googled the error message, but real information about it. It seems that the TDO input pin of BSCANE2 primitive should be connected to somewhere, but I have no idea where to be connected.
 
Has anyone success with this design on the Zedboard?
Thank you in advance!
 
Best Regards,
YM