At night time, the toll system on the M1 between Dublin and Belfast is automated and therefore an intruder alarm system was needed for protection. The distance between the toll booth and plaza is 6.2 kilometers and the security systems – SPC and video cameras – had to be able to connect and operate over that distance so that operators could get an overview of activity at each site. Vanderbilt’s SPC was recently deployed to act as part of the security and communication solution between the toll booth and plaza.

SPC replaced an existing legacy product that had the IFS fiber drivers connected and working on multimode fiber over the 6.2 kilometer distance. The fiber driver was bespoke because of the distance. Multimode is usually only specified for approximately two kilometers. However, when the 3GS legacy system was replaced by a new SPC panel, the communication over the fiber link stopped working.
The installation company, Precision Security, previously had to deploy a pair of fiber cables – two transmitters and two receivers – to transmit the signal back and forth successfully. However, in updating the site, they found that a single pair of ComNet fiber units, straight from the box, could successfully execute the task, despite only being specified for 4.5 kilometers. The Com Net FDX60 multimode fiber units allowed the SPC X-Bus transmission to be converted from RS485 protocols to optical and back to RS485. This enabled the data between the SPC expanders to travel further distances.

Transparent
The FDX60 (M,S)[-M] data transceivers provide point-to-point transmission of simplex or duplex EIA RS232/RS422/RS485 (2W/4W) data signals over one or two optical fibers. The transceivers are transparent to data encoding, giving wide compatibility. Models within this series are available for use with multimode or single mode optical fiber.
“Com Net came straight out of the box and was easy to use and to install. Its threshold is only around four kilometers, but it is working well beyond that. We previously worked with fiber managed switches from the same manufacturer, and we found that they always work as a sweet as a nut,” said Victor Fields of Precision Security, who installed the fiber solution on site.