... RS485(optional) industral programmable logic controller,WECON plc,compatible with Mitsubishi Model LX2N-40MR-A(AC100-240V,24x 24V ... ),meet JEM-1021 standards,between power port and earth terminal. Insulation resistanceDC500V insulation tester test above 5MΩ, meet ... third kind of earth connection(do not share one place with high voltage system) *1Operating environmentClose corrosive,combustible gas, ...