The Input/Output Unit with Isolator provides two voltage-free, single pole, change-over relay outputs, a single monitored switch input and an unmonitored, polarised opto-coupled input.
The Input/Output Unit supervises one or more normally-open switches connected to a single pair of cables.
The Input/Output Unit is fitted with a bi-directional short-circuit isolator and will be unaffected by loop short-circuits on either loop input or output.
The Input/Output Unit is loop powered and operates at 17-28V DC with protocol voltage pulses of 5-9V.
The unit will operate only with control equipment using the Odyssey protocol.
The Input/Output Unit is normally supplied with a backbox for surface mounting. It is also available without the backbox for flush mounting. Both versions are designed for indoor use only.
Four LEDs, two red and two yellow, are visible through the front cover of the enclosure.
One red LED is illuminated to indicate that the relay is set. The second red LED is illuminated to indicate that the switch input is closed.
One yellow LED is illuminated whenever a fault condition (open or short circuit) has been detected.
The other LED is illuminated whenever the built-in isolator has sensed a short-circuit loop fault.
The enclosure is moulded from the same polycarbonate as Odyssey detectors.