control-web CBW - 4 Relay C / SPDT Expansion Module

With a ControlByWeb X-400 or X-600M controller module connected with an expansion module like the X-21S provides an easy, flexible, and reliable way to monitor and control systems and devices over your network. The CBW X-21S is ideal for use with moderate loads such as solenoid valves, alarms, and indicator lights.

Required Controller

One or more X-21s expansion modules can be connected to an CBW X-400/X-600M controller with an expansion cable. The expansion cable provides both power and communications to the expansion modules.