The GV-IO Box 16 provides 16 inputs and 16 relay outputs. It supports both DC and AC output voltages, and provides a USB port for PC connection. 16 inputs and 16 outputs are provided. Up to 9 pieces of GV-I/O Box 4/8/16 Ports can be chained together. A USB port is provided for PC connection, and it is only used for 30 DC output voltage. Up to 5 connections from GeoVision software are allowed to control one GV-I/O Box. Optional support for an Ethernet module (not included).