The CA-A460-P Relay Expansion module provides an additional seven relays to the CT-V900-A controller. Up to two “plug and play” relay expansion modules can be added to each controller for a total of 16 relays per controller. The relay expansion modules are connected to the controller via a RS-485 E-bus network, allowing you to install the relay expansion modules a maximum distance of 1220m (4000 ft.) from the controller. The module features an activation status LED for each relay, a communication failure LED with an associated output, a 24-hour anti-tamper input and supply monitoring. Removable terminals are optional.