I accidentally flashed the 7I98 BIT file onto a 7I92 board. Now the 7I92 can no

I accidentally flashed the 7I98 BIT file onto a 7I92 board. Now the 7I92 can no longer communicate with the host. How can I recover it?

Then it's a 7i98, so change 7i92 to 7i98 in mesaflash. Or use instead --device ethernet

If you accidentally flashed a Mesa 7I92 with 7I98 firmware you are somewhat up the well known creek.
 The reason is that the Ethernet <--> FPGA connections are different between the 7I92 and 7I98 so you will lose
communications.

There are at least  two possible ways to recover:

1. JTAG (needs a JTAG programmer and Xilinx or generic JTAG software)

2. Trick the card into loading the fallback configuration
You do this by briefly corrupting the configuration data stream just at power up,
Typically by say shorting the DO pin of the flash EEPROM to ground
just at power up (causing a CRC error and loading of the fallback configuration).
If this succeeds, the fallback configuration will blink the init LED so you can tell
that you have loaded the fallback configuration. Once the fallback configuration
has been loaded, you can use mesaflash to re-write a valid user configuration.