Devantech

The dS2832 is an Ethernet connected relay module featuring 32 channels of 16Amp 250Vac relays. Each relay has both normally open (NO) and normally closed (NC) as well as the common available on three terminals. 8 flexible I/O channels with a choice of VFC, NPN, or 12-bit analog input. 

Powered and Controlled from the USB bus.

Relays - 4 with integrated snubbing of the normally open terminals
Power - Powered from standard USB bus 
Control interface - USB with a mini B connector
Relay current - Up to 16Amp @24vdc or 250vac 
Connections - Screw Terminals for N/O N/C and Common contacts.

Acroname MTM-IO-Serial module features adjustable rail GPIO ports, high current drivers, software controlled USB 2.0 hub and serial UART ports, all controlled by BrainStem technology.