The Industrial Raspberry Pi Forum

I connected Revpi core3 with Revpi DIO,Revpi core 3 is ok,but Revpi DIO is not,the LED of Power is red or flash red,and LED of in and out are off.And in shell interface,we can't read the input and write output.I don't know why.

According to the status LEDs of the DIO modle this seems to be a problem that is related to the PiBridge connection. The PiBridge reads and writes cyclic the process image.
Could you check the connections of the X2, X4 and PiBridge plugs according to this tutorial?
Check the output of "piTest -d".
a) No DIO device is listed -> re-check your connections: PiBridge connector, etc., use "piTest -x" to reset the PiCtontrol driver.
b) There is one or more device listed as "not configured" -> re-check the PiCtory configuration, save, restart driver i.e. by "piTest -x".
If the LEDs Power, OUT and IN turn green you just forgot to reset the driver after you have setup the configuration in PiCtory.
To verify if I/O data works you can connect the pins Output 1 with Input 1 and use: "piTest -w Output_1,1; piTest -r Input_1" : should be high, "piTest -w Output_1,0; piTest -r Input_1" : should be low.

Have you set up with PiCtory yet?
Mine blinked red until I made a PiCtory configuration and saved it. The tutorial to this can be found here.
Note that it is important that you place the DIO on the same side in the configurator as it is placed in real life next to the physical device.