When Local Area Networks (LANs) are implemented, there always seem to be one or more stations that are isolated from where the 'action is,' one or more stations which are far from the Ethernet hub. These isolated stations may be in a separate building from the Ethernet hub, or they may even be across an industrial campus. Including these isolated stations in the LAN presents a real 'headache' when it is implemented using 10Base-T, twisted pair, copper cable technology. The maximum distance, which is really set by the CSMA cable sharing protocol, is only 100 meters. This hardly allows including isolated stations in the LAN.

However, the LAN can be extended out to these isolated stations by sending the signals along fiber optic cable. The Model 374 is just the right 'pain killer' for the extension 'headache' when the isolated stations are really far away - for example, as far as 14 km. While meeting the CSMA requirements, it allows the isolated station to be connected to the hub using single mode fiber optic cable. Single mode fiber optics is particularly suited for signaling over such relatively long 'local distances' of 10 km and beyond. Of course, in order to do this LAN extension you will need a Model 374 at the isolated station end to convert the electrical signal to/from copper to light for fiber optic transmission. You will also need another Model 374 at the hub end to do the same conversion, unless the hub has this already built-in. This is just like the illustration shows. Using the Model 374 you can really bring your LAN out to stations quite remote from the 'corporate headquarters.'

You will get some additional side benefits from using the single-mode fiber optic cable to do the LAN extension. You will become immune to interference caused by lightning strikes, a real problem when you are transmitting LAN signals outside to remote stations. You will also have total electrical isolation with the fiber optic cable and not have to worry about grounding problems. This is still another 'headache' when you have different elements of a network connected to different physical grounds, as often happens when you go between buildings.