X-21s with 4 relay outputs is an Expansion Module used with an X-400 or X-600m controller. X-21s have 4 relays each with Form-C / SPDT contacts.
One or more X-21 modules can be connected to an X-400 or / X-600M controller with a flat cable. The flat cable provides both power and communication to the expansion modules.
X-400 / X-600m is multi-functional web-activated industrial I / O controllers. They perform control, logic and monitoring functions similar to a programmable logical controller (PLC). Unlike a PLC, however, these controllers are designed for web-based applications from the bottom.
No add-on software or hardware is required. The controllers can be configured, programmed and tested completely directly in the unit using the built-in web server and a standard web browser. The web setup pages are intuitive and easy to use and do not require special programming skills.
The X-400 / X-600M controllers together with expansion modules, such as X-21S, a light, flexible and reliable way to monitor and control systems and devices over a network. X-21s are suitable for use with moderate loads such as solenoid valves, alarms and indicator lights.
Other expansion modules with different I / O combinations are also available.