Swift Futura error 21

Got a 3 stop swift Futura traction machine. It shuts down with a 21 code. Flash eprom read write error. Does any one have any more info or possible causes for this fault. It does it while in motion and also with no velocity. Also the drive flashes a IXT warning sometimes.

The SPU will need to be sent for repair. They replace the eeprom chip if I'm not mistaken. You should also confirm the 5vdc on spu link but the repair should stop the 21 error

Thanks up n down. That’s what I’m doing. I will update after replaced. Power supply is ok. 5.1v. Ac ripple ok