The SW485 is a 9 channel RS485 Splitter / Hub / Repeater and connects 9 channels in STAR topology
LD232 (long distance RS232) is a set for extended extending RS232 line, maximum working distance 1200m, surge supression, galvanic isolation.
QuidoDuplex ETH is a set of two I/O modules for Ethernet (LAN, computer network) with a special firmware designed specificaly to transmit digital I/Os over Ethernet as an autonomous system.
QuidoDuplex RS is a set of two I/O modules for RS485 line (two wires only) with a special firmware designed specificaly to transmit digital I/Os over RS485 line as an autonomous system