Moxa has released the CN2610 terminal server, which provides dual LAN ports and a “Redundant COM” mode for robust network redundancy. Redundancy is an important requirement for many industrial applications, and different solutions have been developed to keep systems running during equipment or software failure. Special “watchdog” hardware is required to implement hardware redundancy, and a "token" switching mechanism is required at the software level. Dual LAN redundancy involves two separate physical networks that connect a PC host to the terminal server. On the CN2610, the two networks are connected using two built-in LAN ports. On the PC host, two LAN cards will be required. When dual LAN redundancy is implemented, the PC host will have continuous access to serial devices attached to the CN2610, even if one of the networks fails.

Redundant COM

The CN2610's “Redundant COM" mode is specially designed for redundant LANs between serial devices and a host computer. Using the two built-in LAN ports on the CN2610, the host computer connects to the terminal server over two independent LANs. If one LAN fails, data will continue to be transmitted between the serial devices and the host using the other LAN. The main advantage of MOXA’s Redundant COM mode is that the LAN switchover happens instantly. Data transmission between the host and the serial devices will not be interrupted or delayed, even if one of the LANs fails.

Dual Host Redundancy

The CN2610 can also be used to set up “dual host” redundancy, in which two separate hosts connect to the serial devices over two separate networks. If there is a failure at one of the hosts, data will continue to be transmitted between the serial devices and the other host over the other LAN.