The IA-3137-U is an intelligent Power Relay Controller, USB controlled, IA-3000 Series compatible with dual wiring versions. Both controllers include 16 power relays with a contact rating of 32VDC@16Amp and 250VAC@16Amp. Both controllers include dual, Optically Isolated Digital Inputs that might be either of a standard 5VDC to 32VDC range, or 90VAC to 230VAC range. In the IA-3137A-U the relays are grouped into 4 separate groups, while each group includes a common Bus line that simplifies the wiring, while in the IA-3137B-U the relays are wired independently of each other. Both modules are USB controlled, and has a built in capability of daisy chaining additional RS-232 modules, Series-3000 compatible. Each module has a unique permanent ID number, and easily settable chain address, enabling a simple control over several modules, connected to a single USB PC port.