Model 531-8 Digital Input-Output

The 531-8 Digital I/O replaces copper wire and galvanically isolates, protects, and monitors contacts remotely (such as close-coil, local, or remote trip) and supports telemeter revenue meter pulses over large distances. The Model 531-8 is simple to install due to its removable plugin screw terminals. The unit does not require a PC but only a screwdriver to connect the inputs and outputs.

The unit has 8 universal (12-250Vdc) opto-isolated voltage inputs and eight isolated microprocessor fault-protected relay (Form 1A) outputs. Solid-state or electro-mechanical relays are available with optional gold contacts very low resistance, low voltage applications. The Model 531-8 is bi-directional. The inputs on one unit controls, via fiber, the outputs on the mating unit. This allows relaying of electrical status signals without a ground loop while maintaining a floating signal locally. The latched relay outputs remember the state of the data packets sent using CRC checking. If the fiber is severed, or the sending unit loses power, the outputs do not change, which ensures reliable data exchange and no uncommanded operations.

531-8 Digital I/O offers plug-in optical modules for multimode or singlemode fiber operation. You can substitute an RS-232 module for the optical module and connect the unit to an H&L Model 570 transceiver. This allows you to take advantage of the many point to point fiberoptic channels on the 570 system eliminating the need to use additional dedicated fibers.

The use of glass or plastic fiberoptic cable eliminates the challenges typically found in copper, radio, and telco wireline systems. The 531-8 Digital I/O unit includes eight opto-isolated 12-250Vdc inputs and eight isolated, microprocessor fault protected, latched relay outputs. This unit provides the ideal solution for connecting to electrical switchgear such as reclosers and ensures the best performance possible.

Full data sheet

531-8 Application Example

H&L Instruments, L.L.C.
P.O. Box 580, 34 Post Road
North Hampton, NH 03862-0580 USA

Tel. 603-964-1818
Fax 603-964-8881