I have an Omron C200H CPU22 and i try to connect an operator interface on it. It is a NT20M-DN121-V2 (it's not a touch screen) with C200H I/F unit (NT600M-LB121). Omron give no info for the NT600M-LB121 unit. When i connect it on the backplane (C200H-BC051-V1) the plc go in error mode. The error is I/O UNIT OVER. I have removed all I/O for possible conflict. Please help me.