From D0 to D511, the default is not maintained when power off, and D511 is locked after power off by default. So when programming, pay attention to the allocation of data addresses. If you need to keep the power off, try to choose the D area after D511.
befeor D511 can be set as power-off retention range ， after D511 will be power-off retention without setting i
my fx3u-32mt device doesn’t save the value when the power goes out. i tried D600~D5000. is there any way to help me. battery 3v ok.