The Milestone ML 4RLC LV is a four-relay controller designed for the reliable switching and control of low-voltage electrical loads between 3V and 48V from a single control point. Built for boardrooms, conference rooms, small automation projects and AV installations, it lets an operator switch up to four independent devices using the front-panel keypad, a remote keypad, contact closure, or a programmable RS232C interface without needing to be physically present at each load.

Key Features
Four independent relays for switching low-voltage (3V to 48V) loads
Front-panel keypad selection for direct local operation
Remote keypad or contact closure via D9 male connector, operable up to 50 metres away
RS232C interface via D9 female connector for computer or system-controller operation (9600 baud, 8-bit, 1 stop bit, no parity)
Battery-backed relay status memory – relay states are restored automatically after a power cycle
Optical isolation between the RS232C port and relay circuits for safer, more reliable operation
DIP-switch exclusive relay pair mode for forward/reverse motor control
LED indication for each relay and power status
Unit identifier DIP switch allows multiple controllers to be addressed on a single RS232C line

Applications
AV system power control in presentation rooms and boardrooms
Low-voltage lighting control in offices, auditoriums and retail spaces
Motor control for curtains, screens, gates, blinds and actuators using exclusive relay pairs
Building automation and electrical switching from a centralised control point
Equipment control in training rooms, laboratories and demonstration facilities

Summary
The Milestone ML 4RLC LV is a dependable low-voltage relay controller that brings four switching channels together in a compact table-top unit. Its combination of local keypad, remote and RS232C control, battery-backed status memory and optical isolation makes it a practical choice for integrators and facility managers who need to switch low-voltage equipment from one convenient location.