Model 561 Fiberoptic Transceiver
FiberLoop II System

The Model 561 is a field-tested fiberoptic transceiver that combines with the FiberPanel Windows-based network management software to implement the H&L Instruments FiberLoop II system. The 561 transceivers are employed in very large networks to connect Remote Terminal Units (RTUs) or other Intelligent Electronic Devices (IEDs) with a Model 561 configured as a SCADA master or network controller.

The Model 561 FiberLoop II System:

When used as a master unit, the Model 561 is the head end for the SCADA masters. All signals pass through the controller, which can automatically self-heal  the system and re-route data in the event of fiber cuts or a transceiver failure anywhere in the system. The arrangement of transceivers in a loop configuration provides a highly reliable, fault-tolerant solution, and FiberLoop II deployed in small systems can provide a dedicated channel for each RTU.

Model 561 transceivers can be placed in a system as standby controllers at any location connected to a standby SCADA master computer. This allows the standby controllers to take over the FiberLoop II operation in the event that the primary controller fails. As many as 250 additional Model 561 transceivers can be added to the system and, dependent on options, four, eight or sixteen RTUs or other IEDs can be connected to each unit. In addition, 32 devices can be multi-dropped on an optional RS-485 port.

16 Virtual Channel Option

The Model 561-16 adds 16 virtual channels to the Model 561. It provides multi-drop, multi-channel serial data communications for master/slave supervisory control and data acquisition systems (SCADA). In controller mode, this device automatically reroutes data in the event of a fiber break or transceiver failure. In transceiver mode, the device provides the interface with all remote devices including RTUs, PLCs, and IEDs.

Both the Model 561 and 561-16 transceivers are bundled with the FiberPanel configuration and diagnostic software.

Related articles and papers


Model 561 data sheet

Model 561-16 data sheet

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