ADS1261EVM: Communication with custom board using ADS1261EVM

Hello, 

I have a custom board implementing the ADS1261 using Bipolar supply: +2,5V and -2,5V at AVDD and AVSS, respectively.

I'm trying to talk to it using the Delta-Sigmal software + ADS1261EVM.

I have removed ALL Digital Signal connection on the board, that means, I removed these resistors:

and connected the SPI communications from the EVM board to my custom board (CS, DIN, DOUT, SCLK & GND).

However, it's not communicating anything, the Orange FAULT LED is ON and no communications are being made: CS pin is always HIGH.

Question 1: How do I bypass this fault detection to get the boards communicating?

On my custom board, I have checked these things:

• The voltage at BYPASS pin is 2,0V.
• Question 2: I measure REFOUT to be -2,5V, is this correct?

Thank you very much in advance.

Best Regards,