W&T connects
Interfaces for TCP/IP, Ethernet, RS-232, RS-485, USB, 20mA, glass and plastic fiber optic cable, http, SNMP, OPC, Modbus TCP, I/O digital, I/O analog, ISA, PCI
Product overview:

Interfaces for USB, RS232, RS422, RS485 and 20mA

Serial <> Serial Interfaces

USB <> Serial Interfaces

Serial Buffers and T-Switches

Cables and Connectors